iam getting a small problem

Without your code, we can't say exactly, but...the error message does give you the basic info you should need to fix it yourself: See those two numbers at the end? "24 13" are the line and column numbers at which it noticed the problem in your file.

So go to Default.aspx.cs and look at line 24. Something about it is trying to use "hashtable" - you need to look at it, and find out what. The normal problem is that you have a namespace "hashtable" and a class "hashtable" and the compiler isn't sure which you mean. In that case try "hashtable.hashtable" to properly specify exactly what you mean.

Basically you have created a namespace that ends with Hashtable and then you have attempted to use a Hashtable in your code. If you really need to keep the Hashtable namespace, then you could simply change the declaration of your Hashtable type in code to use the full namespace to identify it:

private System.Collections.Hashtable _hashTable = new System.Collections.Hashtable();