Question

I need to get the user’s screen resolution and save it my database.

What I’m doing is this: I have a Javascript function called with that gets the info and passes the value to a hidden form field. This is the function:

<script type="text/javascript">

function getUserData(){

var s_width=screen.width
var s_height=screen.height
document.getElementById('screen_width').value=s_width
document.getElementById('screen_height').value=s_height

}

</script>

And the form:

<form name="login" id="login" action="memberlogin.php" method="post">
<input type="hidden" id="screen_width" name="screen_width">
<input type="hidden" id="screen_height" name="screen_height">
<table style="margin-top:9px;">
<tr><td width="200px"><input type="text" name="username" style="width:100%"/></td></tr>
<tr><td width="200px"><input type="password" name="password" style="width:100%"/></td></tr>
<tr><td><input type="submit" name="submit" value="Log In" /></td></tr>
</table>
</form>

The form submits to the same page. When I click ‘submit’ and try to echo the value of $_POST[‘screen_width’] and $_POST[‘screen_height’], nothing happens. But when I re-submit it, the values are there. Can someone tell me what am I doing wrong? If you have an alternative solution, it would be equally appreciated.

Answer 1

Solved it myself, it was just a matter of calling the function after loading the element.