url validation

[briton]

i've just wrote this url validation. it works alright till i dont enter url-s like www.genie.co.uk or www.astalavista.box.sk lets say. the real problem is with the string that comes at the last place, i cant restrict it from being more than 3 chars because of the optional dot before it. once u have a look at the validation u'll see it. i'm not good with explanations🙁 if anybody can offer a suggestion, i'll appreciate it!
here it is:
ereg ("^{(http://www|www).([-,_])([a-z,A-Z,0-9]+).{2,3}[.]?(([a-z,A-Z]){2,3})[/]?[~]?([/,a-z,A-Z,0-9]+)?$",$url);}

[keegan]

This is just one problem with your regexp - another that jumps right out it that it will only accept URLs beginning with 'www', which doesn't make any sense. Here's the one I use, which hasn't given me any problems:

<?php
function verify_url($url) {
return eregi("^{((ht|f)tp://)((([a-z0-9-]+(.[a-z0-9-]+)(.[a-z]{2,3}))|(([0-9]{1,3}.){3}([0-9]{1,3})))((/|\?)[a-z0-9~#%&'_+=:\?.-])*)$",} $url);
}
?>