Any rules regarding button order?
Order of items in a context menu
What medium should be used for long term, high volume, data storage (archival)? Should form 'Continue' button be disabled if validation is incomplete? In forms we often see the 'continue' button inactive until all the required fields are complete:         &ndash; Wireframes created with   Is this actually a help to the user, or a hindrance?  I imagine the Pro for this is that it's a visual indicator to the user that they haven't finished filling in the form or dealing with errors (because even with inline validation a user won't be informed if they've never actually interacted with a field so won't show any errors for those at that point).  But then the main Con for this (which I've also seen borne out in usability testing) is that users will be confused why they can't click the button.  Is the pattern of disabling the Continue button until validation is complete actually providing a negative user experience? How a module can override theme suggestion? Basically it was  but I'll reword it, as I don't want to define a new theme (reason was already given).  What I want to do: in my module I have a file node--attach.tpl.php which is a modifed version of node.tpl.php. Now I want that, if view_mode = 'attach' then this file is used. Also, theme should be allowed to override it with its own node--attach.tpl.php in theme folder. Err 80 appears when I turn on my Canon EOS 5D Mark II Continuously Differentiable Curves in $\mathbb{R}^{d}$ and their Lebesgue Measure Show that the image of the curve $\Gamma\in\mathscr{C}^{1}\left([a,b]\to\mathbb{R}^{d}\right)$ has d-dimensional Lebesgue measure zero (of course, $d\geq2$).  This can be proved using the absolute continuity of $\Gamma'$ (since $[a,b]$ is compact and $\Gamma'$ is assumed continuous, hence in $L^{1}([a,b])$) together with the fundamental theorem of calculus to obtain an $\epsilon$-small cover of $\Gamma$ by balls.  But I am trying to prove this using more elementary means (i.e. without integration).  Intuitively, since $\Gamma$ is smooth, we ought to (for fine enough partitions) be able to cover $\Gamma$ by boxes which arise from its tangent line.  And by taking the partition of $[a,b]$ to be finer and finer, the "tangent box" cover ought to also get smaller and smaller.  More rigorously, the vector-version of the mean value theorem can be applied: $$|\Gamma(t_{i-1})-\Gamma(t_{i})|\leq(t_{i}-t_{i-1})|\Gamma'(t_{i}^{\star})|\leq M_{i}\Delta t$$ where $t_{i}^{\star}\in(t_{i-1},t_{i})$ and $M_{i}=\sup_{t\in[t_{i-1},t_{i}]}|\Gamma'(t)|$ which exists and is finite since $\Gamma'$ is continuous.  But to me, it's not quite clear how to rigorously construct a cover by boxes from here.  NOTE:  In the proof I mentioned (using integration), essentially you sum the left hand side over all partition intervals of uniform length $\delta$ (which depends on the $\Gamma'$), and "integrate" the right hand side.  Actually, to be more specific, for each $\epsilon&gt;0$ there exists a $\delta&gt;0$ such that $||P||&lt;\delta$ implies $\int_{t_{i-1}}^{t_{i}}|\Gamma'(t)|dt&lt;\epsilon$ (e.g. absolute continuity).  This allows you to define numbers $\epsilon_{i}=\sup_{t,\bar{t}\in[t_{i-1},t_{i}]}|\Gamma(t)-\Gamma(\bar{t})|\leq\epsilon$ so that $\sum_{i=1}^{\#P}\epsilon_{i}\leq||\Gamma'||_{L^{1}([a,b])}$.  Then you can use these $\epsilon_{i}$ to put balls at each point $\Gamma(t_{i})$ of radius (say) $2\epsilon_{i}$, thus giving you an $\epsilon$-small cover.  Again though, this is harder to establish without integration theory. How to change the chapter number to display as text (One, Two, ...)? mysql select distinct rows into a comma delimited list column When should I use "didn't" instead of "haven't"? Is haven't supposed to mean something I may still do and didn't not?  Can I use didn't for something I might still do? After the DEM creation, I wanted to create slope layer.   However, the result has not satisfied me. I don't think the slope map is correct. Have you ever encountered false calculated terrain map?  This is the DEM:    And this is the slope layer. I'm working from the URL I found here:    My ssh client is Ubuntu 64 bit 11.10 desktop and my server is Centos 6.2 64 bit. I have followed the directions. I still get a password prompt on ssh.  I'm not sure what to do next. Find equation of a plane that passes through point and contains the intersection line of 2 other planes Find equation of a plane that passes through point P $(-1,4,2)$ that contains the intersection line of the planes  $$\begin{align*} 4x-y+z-2&amp;=0\\ 2x+y-2z-3&amp;=0 \end{align*}$$  Attempt: I found the the direction vector of the intersection line by taking the cross product of vectors normal to the known planes. I got $\langle 1,10,6\rangle$. Now, I need to find a vector normal to the plane I am looking for. To do that I need one more point on that plane. So how do I proceed? Who are the clients of my shared iTunes library? Is it possible to see who is currently connected and listening to a shared iTunes library? Is it possible to see which songs they listen to and how many/often?  It's not really important; I'm just curious about it. Would be nice to know which colleagues love my music… When a body lies on the surface of the Earth it is under the influence of gravity. The force on the body due to gravity causes it to exert a force on the ground and the normal reaction acts in the opposite direction causing the resultant force on the body to be zero.  However, how can the body exert a force on the ground when it does not have any acceleration? Since force equals mass times acceleration how does a body without acceleration experience a force? This occurs in the  released recently to the public. When someone posts a code block in their question or answer, the code block is cut off on the right hand side, and I can't scroll to the right to view the rest of it. How can I view these code blocks? Why do video cables (DVI, VGA) still screw in? I guess I could imagine that there was a time when accidentally disconnecting the monitor would have been catastrophic, though I don't see that being the case today.  Is it just a legacy holdover that they are still secured with screws?  Also, why is it that the video connection is really the only one that is still secured this way?  It seems like the power cable would be a better candidate to be secured with screws.  That really could be catastrophic.  In the end, the reason this question occurred to me is that I've never had a video cable come out when not screwed in, so why the significant security? Core Data - Storing Images (iPhone) MicroSD card is set to Read-only state. How can I write data on it? Looking for sci-fi short story anthology with a particular story of an Earth/Mars war children inheriting the surface I read this in the early to mid 80's.  It was a textbook sized hardcover anthology with color illustrations throughout.  Each story had a few images, some were full page illustrations.  The particular story I remember the most involved Earth survivors living underground.  Robots controlled the war from the surface.  A teenage girl and boy decided to sneak away to the surface as no one had been up there in a long time.  The kids discover greenery and a healthy environment, with rusted robot guardians.  The robots had been keeping the humans fooled that the war was still going on, and had kept them under the surface.  Mars had been wiped out from nearly the first volleys of missiles.    The robots judge the teenagers as worthy and let them remain on the surface.  The kids had silver jumpsuits that dissolved when they got wet.  The robot illustrations were blocky, almost weathered stone-like statues.  They had nearly spherical feet and square simple heads.  The faces had eyes and simple mouths.  -edit- The robots were similar in shape to the one in this picture, but smoother, and no arms.  The illustrations with them had the robots being several stories tall.  I kind of remember that the kids emerged from the belly of one or something like that. List of apps ever downloaded Show that $\arctan(n)$ is irrational for all $n \in \mathbb{N}$