Is it possible to have an overloaded function in classic asp JScript
Not. The last function will overwrite / replace functions with the same name as before it.
Read How to Duplicate ASP Function Descriptors (vbscript)
Not. The last definition of function is the one to be used.
To make the best use of the function, add functionality in different contexts, try using one of the methods described in Overloading Functions in Javascript - Best Practices , or perhaps this technique mentioned by John Resig may be better suited for your purposes.