Single and double quotes in form fields will not write to Mysql database. Is there a solution?
How can I prevent SQL injection in PHP?
How to back up my entire system? If I want to make a backup of my entire OS (including but not just my home directory), how do I go about this?    Is it as simple as backing up everything in / and then when if I suffer a crash, just copying the files back over? Will this cover grub, and how do I actually do this when the system is inoperable? I'm looking for a true 360 degree camera, so that's both vertical and horizontal 360 degrees. I've seen some clip-ons for the iPhone, but am really not wanting to by an iPhone 4S for this.  What I would like to see: - decent resolution: at least 1920x1080. - and 30fps  I can't settle for an alternative that's not vertically 360 degrees (or at least much more than 180 degrees).  I've seen the ball camera, which isn't out yet, but would be really well suited for my case, given it does video as well. When is a CDATA section necessary within a script tag? Are CDATA tags ever necessary in script tags and if so when?  In other words, when and where is this:  &lt;script type="text/javascript"&gt; //&lt;![CDATA[ ...code... //]]&gt; &lt;/script&gt;   preferable to this:  &lt;script type="text/javascript"&gt; ...code... &lt;/script&gt; How to activate hyphenation in \ttfamily without explictly setting a font? I am suprised that in the code below no hyphenation is done. And I can not find something about that on the web. Maybe I used the wrong words for searching.  \documentclass{scrartcl} \usepackage{xltxtra} \usepackage{polyglossia} \setdefaultlanguage[spelling=new]{german} \usepackage{tabu}  \begin{document} \begin{ttfamily} \begin{tabu} spread \textwidth {X[l]|X[l]|X[l]|X[l]}     A&amp;     B&amp;     Sichtweise, Haltung, Akzeptanz, useability, Anwenderfreundlichkeit&amp;     D\\ \end{tabu} \end{ttfamily} \end{document} Prove that $\lfloor\lfloor x/2 \rfloor / 2 \rfloor = \lfloor x/4 \rfloor$ Is it correct to write $\Bbb E[X]$ or $\Bbb E_{\theta}[X]$? Suppose that we observe the discrete random variable $ X = (X_1, \dotsc , X_n)$ with state space S, whose distribution we do not know but we are assuming that its joint p.m.f. belongs to a known family $\{f_θ : θ ∈ Θ\}$. We derive a sufficient statistic $T(X)$.  Is it correct to write $\Bbb E[X]$? If not, why? Would it be more correct to write $\Bbb E_{\theta}[X]$? How to manage users and groups using GUI? Just switched from 10.04 to 11.10. I'm wondering about the limited options in the GUI for managing users and groups. Where is the old GUI to change groups, id's, etc. I know that I can do this from cli, that's no problem. But I want this comfortable GUI back. Show that $\textbf{ZF}$ shows $\phi$ is $\Delta_1$ Consider $\mathbb R^{[0,1]}$ the space of all functions from $[0,1]$  to $\mathbb R$  and the cylindrical sigma algebra $\mathcal B$  on it. The question is: how to prove that $C[0,1]\notin \mathcal B$. Ubuntu 14.04 LTS fails to start with a kernel panic Word for a temporary project name In software development, and I imagine in many other fields, we often make up temporary nicknames for new projects or features. These are not meant to be the real names for the end product and are often funny, playful, or sarcastic in nature. These are also not intended to be "codenames" that hide the nature of the project or feature. Is there a word for such nicknames? Prove Uncountable set minus a countable set is uncountable Let B be a countable set, and let A be an uncountable set. Prove that A-B is uncountable Will be glad for a little hint: let x and n be positive integer such that $1+x+x^2+\dots+x^{n-1}$ is a prime number then show that n is prime Hint:  $a^2 -ab +b^2 = (a+b)^2 -3ab.$  I know we can say that there exists an $x,y$ such that $ax + by = 1$.  So in this case, $(a+b)x + ((a+b)^2 -3ab)y =1.$  I thought setting $x = (a+b)$ and $y = -1$ would help but that gives me $3ab =1.$  Any suggestions? @class vs. #import It is to my understanding that one should use a forward-class declaration in the event ClassA needs to include a ClassB header, and ClassB needs to include a ClassA header to avoid any circular inclusions. I also understand that an #import is a simple ifndef so that an include only happens once.  My inquiry is this: When does one use #import and when does one use @class? Sometimes if I use a @class declaration, I see a common compiler warning such as the following:     warning: receiver 'FooController' is a forward class and corresponding @interface may not exist.   Would really love to understand this, versus just removing the @class forward-declaration and throwing an #import in to silence the warnings the compiler is giving me. What's the difference between an id and a class? Determine the number of lines within a text file Is there an easy way to programmatically determine the number of lines within a text file? Proving $\prod \limits_{k=0}^{n}(1-a_k) \geq1- \sum\limits_{k=0}^{n}a_k$ If $x_1,...,x_n$ are positive real numbers and if $y_k=1/x_k$, prove that $$\left(\sum^n_{k=1}x_k\right)\left(\sum^n_{k=1}y_k\right)\geq n^2.$$   I've been learning induction, and I've come across this problem that I really can't even break down and begin to think about. I've been told it has something to do with Cauchy-Schwarz, but I cannot figure out how to apply it. I would appreciate help figuring out how to go about and formulate this proof. Thanks! Render not showing UV texture