commers messing forms up

[master82]

I have the following form:

[code]
<form action="docalc.php" method="post" name="calcform" target="_self" id="calcform">
    <label>
    <input name="calc" type="text" id="calc" value="<?php echo"$max" ?>" />
    </label>
          <label>
          <input name="Submit" type="submit" id="Submit" value="Submit" />
          </label>
  </form>
[/code]

But when the data is submitted I get errors because some people enter 500000 for example while other enter 500,000 and others 500'000.

Its these , and ' etc that messup the calculation.

So how do I strip out ANYTHING that is not a number?

I've looked at the php manual webby but I couldnt figure it out (stripslashed etc...)

Anyone able to help?

[wildteen88]

Prehaps do something like this:
[code=php:0]$max = str_replace(array("'", ",", " "), "", $max);[/code]