generate password with specified characteristics
Calculate active URL of an array for validation (can be used for multi URL sites (e.g. dyndns)
get the ip address from the client, even if the client is befind a proxy (it doesn't work with transparent proxy!)
Cleanup text from invalid characters for filename
calculates CSS font sizes. This is a small solution, that the appearance looks similar with different browser types and operating systems
Get formular error messages
create unique identification string
Return size of image file
returns value of special variable type from user input (If register_globals is Off (default since 4.2.0), this function can be used, to handle user variables (insecure variables).