Allow only certain ctrs in text box

[bulrush]

If I have a text box for user input like this:

$s='<td><input type="hidden" name="txtMID[]" value="'.$row['mid'].'" size="6" />';
echo "$s\n";

 

How do I allow only certain characters, like letters (upper and lower case) and digits? How do I allow some characters like ampersand, at sign, dollar sign, question mark?

 

Thanks.

 

[F1Fan]

You'll need to either use JavaScript to validate before the page is submitted, or PHP to do it after the fact.

[bulrush]

How do I do this with Javascript?

 

[F1Fan]

Well, without completely writing the code for you, here's an example of something I wrote that only allows numeric entries:

$s='<td><input type="hidden" name="txtMID[]" value="'.$row['mid'].'" size="6" onkeyup="this.value=getNumeric(this.value);" />';
echo "$s\n";

function getNumeric(text){

if (!isNumeric(text)){
	text = '';
}

return text;
}

function isNumeric(sText){
var ValidChars = "0123456789.-";
var IsNumber=true;
var Char;
for (i = 0; i < sText.length && IsNumber == true; i++){
	Char = sText.charAt(i); 
	if (ValidChars.indexOf(Char) == -1){
		IsNumber = false;
	}
}
return IsNumber;
}

[bulrush]

In other words I have to use a PHP function which does the brute force method, or perhaps uses a regex?

 

I can't use the pattern attribute? Well, I can't see how the pattern="" attribute would display an error message.

 

[F1Fan]

Both of the functions that I listed are JavaScript functions. And, yes, you could use regex to modify what I sent. Or, you could even add what you want as valid characters to the "ValidChars" variable.