Javascript change getHours to 2 digit
How can I pad a value with leading zeros?
Is it possible to make my laptop's screen act as a second monitor for my desktop computer? How to upload files to server using JSP/Servlet? How do I boot from ISO file stored on hard disk? In the category $\mathbf{Set}$ is "the product of an empty set of sets a one-element set"? I was reading  on Category Theory and it said (paraphrased to add context):     Exercise 4: Explain why in $\textbf{Set}$ (the Category of Sets), the product of an empty set of sets is a one-element set.   which I think is incorrect. The product of two empty sets (or any number) is empty because we are considering:  $$ \emptyset \times \emptyset = \{ (a,b) : a \in \emptyset, b \in \emptyset \} = \emptyset$$  where $a \in \emptyset , b \in \emptyset$ are false, so the above is the $\emptyset$ which is NOT a one element set (its a zero element set).   This should be trivial so I am assuming I am somewhere mis reading the natural language of the exercise. Someone help me catch where is it and what the answer should be? i.e. whats being asked and the answer? Texture mapping with multiple UV maps So, as a newbie relatively new to blender, I started doing some texture mapping (blender internal Render). I created a texture for the main object and a couple of transparent decals to decorate it. (basic effects made in GIMP). Simple stuff, just to know how it works.  After unwrapping, having 2 UV maps made, creating both new material and textures, enabling UV mapping coordination I always end up with:  - all - 1 faces of the cube being covered nicely in the main texture  - 1 face covered in blank material with a decal in the middle of it  - the whole thing partly coated by a huge "stain" of a decal  So, the problem is that I can't layer textures correctly. Is there a way to have one texture covering everything and more transparent ones on top of it? I am working on a bigger project right now and having this ability would be useful What's the difference between STDIN and arguments passed to command? Can I pay two different costs with the same payment? I'm new to Ubuntu, it looks like it is better than Windows. Last day I tried to install Kget (the download manager) but during the process my computer suddenly stopped working. So I had to switch it off. After I logged into Ubuntu again I can't install any program. The Ubuntu Software Center says:  Items cannot be installed or removed until package catalog is repaired. Do you want to repair it now?   After I clicked repair it says (after few seconds):  Package operation fails - The installation or removal of a software package failed   I've tried several times, but the same problem occurred. Can anyone tell me a solution for this problem? How can I prove $\sup(A+B)=\sup A+\sup B$ if $A+B=\{a+b\mid a\in A, b\in B\}$ If $A,B$ non empty, upper bounded sets and $A+B=\{a+b\mid a\in A, b\in B\}$, how can I prove that $\sup(A+B)=\sup A+\sup B$? What packages do people load by default in LaTeX? How do I install an older version of an app on an iPhone? Let $f:[0,\infty)\rightarrow [0,\infty) $ be a continuous strictly increasing function and $g=f^{-1}$. Let $a,b&gt;0$ and $a\neq b$. Then how $\displaystyle\int_{0}^af(x)dx+\int_0^bg(y)dy\geq ab.$ Any hint will be appreciated. I discovered that you can start your variable name with a '@' character in C#.  In my C# project I was using a web service (I added a web reference to my project) that was written in Java. One of the interface objects defined in the WSDL had a member variable with the name "params". Obviously this is a reserved word in C# so you can't have a class with a member variable with the name "params". The proxy object that was generated contained a property that looked like this:  public ArrayList @params {     get { return this.paramsField; }     set { this.paramsField = value; } }   I searched through the VS 2008 c# documentation but couldn't find anything about it. Also searching Google didn't give me any useful answers. So what is the exact meaning or use of the '@' character in a variable/property name? Transpose some columns to rows using pivot with SQL @username auto-completion for comments was , and is already active on MSO.  However, it only seems to auto-complete the usernames of people who have commented on the post. According to , the list of users who can be explicitly notified also includes:   Anyone who edited the post Anyone who started a bounty on the question The &diams; moderator or  who cast a binding close vote on the question   Why not auto-complete those, as well? Using [Authorize] without SimpleMembershipProvider What is a good replacement for a cable end cap? I was adjusting the tension of my front derailleur cable and managed to pop off the cable end cap. The cable is now quite frayed at the end and I think it would be difficult to attach another cap.  What would work as a suitable replacement for a cap? I've read that perhaps superglue or duct tape could work? How do I get the value of a textbox using jQuery? I have a page where some event listeners are attached to input boxes and select boxes. Is there a way to find out which event listeners are observing a particular DOM node and for what event?  Events are attached using:    Event.observe; DOM's addEventListener; As element attribute element.onclick. Does anyone know if there are any video formats (besides the HUGE uncompressed avis) that you can render in that maintain the alpha channel? (i.e. for after FX etc.)   I used to use quicktime, but that's no longer an option.  I know you can render in png. or other image formats, but video is significantly smaller, and I often work on machines with less space &amp; resources.