Listing 1
<cfscript>
/**
* Changes a var in a query string.
* 
* @param name The name of the name/value pair you want 
to modify. (Required)
* @param value The new value for the name/value pair you 
want to modify. (Required)
* @param qs Query string to modify. Defaults to 
CGI.QUERY_STRING. (Optional)
* @return Returns a string. 
* @author Nathan Dintenfass (nathan@changemedia.com) 
* @version 2, September 5, 2002 
*/
function QueryStringChangeVar(variable,value){
//var to hold the final string 
var string = "";
//vars for use in the loop, so we don't have to evaluate 
lists and arrays more than once
var ii = 1;
var thisVar = "";
var thisIndex = "";
var array = "";
var changedIt = 0;
//if there is a third argument, use that as the query 
string, otherwise default to cgi.query_string
var qs = cgi.query_string;
if(arrayLen(arguments) GT 2)
qs = arguments[3];

//put the query string into an array for easier looping
array = listToArray(qs,"&");
//now, loop over the array and rebuild the string
for(ii = 1; ii lte arrayLen(array); ii = ii + 1){
thisIndex = array[ii];
thisVar = listFirst(thisIndex,"=");
//if this is the var, edit it to the value, otherwise, 
just append
if(thisVar is variable){
string = listAppend(string,thisVar & "=" & value,"&");
changedIt = 1;
}
else{
string = listAppend(string,thisIndex,"&");
}
}
//if it was not changed, add it!
if(NOT changedIt)
string = listAppend(string,variable & "=" & value,"&");
//return the string
return string;
}
</cfscript>



Listing 2
<cfscript>
/**
* Deletes a var from a query string.
* Idea for multiple args from Michael Stephenson 
(michael.stephenson@adtran.com)
* 
* @param variable A variable, or a list of 
variables, to delete from the query string. 
* @param qs Query string to modify. Defaults to 
CGI.QUERY_STRING. 
* @return Returns a string. 
* @author Nathan Dintenfass (nathan@changemedia.com) 
* @version 1.1, February 24, 2002 
*/
function queryStringDeleteVar(variable){
//var to hold the final string
var string = "";
//vars for use in the loop, so we don't have to evaluate 
lists and arrays more than once
var ii = 1;
var thisVar = "";
var thisIndex = "";
var array = "";
//if there is a second argument, use that as the query 
string, otherwise default to cgi.query_string
var qs = cgi.query_string;
if(arrayLen(arguments) GT 1)
qs = arguments[2];
//put the query string into an array for easier looping
array = listToArray(qs,"&"); 
//now, loop over the array and rebuild the string
for(ii = 1; ii lte arrayLen(array); ii = ii + 1){
thisIndex = array[ii];
thisVar = listFirst(thisIndex,"=");
//if this is the var, edit it to the value, otherwise, 
just append
if(not listFind(variable,thisVar))
string = listAppend(string,thisIndex,"&");
}
//return the string
return string;
}
</cfscript>