Hey everyone,
This is the function I use when replacing url variables, or adding a new variable.

I realize there are holes but for the most part as long as there are no crazy characters in the url or the variables you will be ok.

PHP Code:
function replaceUrl($url,$uKey,$uVal){
    
$Qurl explode("?",$url);
    
$arr explode("&",$Qurl[1]);
    
$r ''$set 0;
    for(
$i=0;$i<sizeof($arr);$i++){
        
$arr2 explode("=",$arr[$i]);
        if(
$arr2[0] == $uKey){
            
$arr2[1] = $uVal;
            
$set 1;
        }
        
$r.=$arr2[0]."=".$arr2[1]."&";
    }
    if(
$set == 0){
        
$r.= $uKey."=".$uVal;
    } else {
        
$r rtrim($r"&");
    }
    return 
$Qurl[0].'?'.$r;

usage:

PHP Code:

print replaceUrl('http://yourDomain.com/index.php?test=1&name=rlemon&age=19','name','rob lemon');