PHP Validate Input Function

A custom input validation function. It protects against MySQL injection and URL exploitations. In short, it is a great function for validating user input (examples such as login forms or email forms).

function validate($input)
{
    return str_replace(array('\\','(',')','#', ';','&', '%', ' '),'',trim(htmlspecialchars(preg_replace('/[^a-zA-Z0-9_ %\[\]\.\(\)%&-]/s', '', $input), ENT_QUOTES)));
}