Here you go, this should work:
function isValid($varx)
{
$valid = true;
$nix = array("#","(",")","<",">","?","/","\\","[","]","|");
for($index=0;$index<strlen($varx);$index++)
{
if(in_array(substr($varx,$index,1), $nix))
{
$valid = false;
}
}
if(substr($varx, 0, 1) == " ")
{
$valid = false;
}
return $valid;
}
$var seems to be invalid for a variable name hence the use of $varx