[Zope] <dtml-call > Problems

[Karl Munroe]

I have this code segment in a dtml method:

<dtml-call
"RESPONSE.redirect(URL1+'/MathodName?var1='+var1val+'&var2='+var2val+'&var3=
'+var3val)">

It seems as if I am doing something wrong. I get the the following error
message :

Zope has encountered an error while publishing this resource.

Error Type: TypeError
Error Value: illegal argument type for built-in operation

I have tried the above code before many times and it worked. If I remove
var3 from the redirect string everything goes fine. Is there a limit to the
number of variables you can pass in the query string section of the URL?

Thanks in advance
Karl