EXAMPLE: I’ve got a string that contains the following info:
$string = "This is just a sample string. Don't take it too litterally. You've got the ca$h.";
How do I search the string to find the $ character so I can handle an error(specifically, to restrict specific characters from being entered in a form, and return a custom error message if the user entered in that character)?
Thanks in advance to all of you! 
