vairable name as value of another variable, ASP classic

[SoonerDude]

i would like to make a function that takes the variable name as a string, check if exist a querystring, or a request.form or a variable with that name and return the value.\[code\]function revalue(varName) if request(varName) <> "" then revalue= http://stackoverflow.com/questions/14523097/request(varName) else revalue="" end ifend function\[/code\]how can i check if the variable called as the value of \[code\]varName\[/code\] exist and has a value?