ASP.NET Request

So I'm progamming ASP.NET today.
There are still some things I am not aware of. as there were many was not aware of until meeting them. Take this for example:

Somewhere in the code programmer wrote:

string requestParameterValue = context.Request[requestParameter] == null ? "": context.Request[requestParameterName].ToString();

if(requestParameterValue != "")
{
// do a GUID from the requestParameterValue ...
}

this worked until the code "meet" a piece of code writen by some other programmer. This other programmer was putting on request (on QueryString) some data to pass like clientCode - clientName. No URL Encription, no nothing !

For example (names changed for privacy issues) :
0001 - A company
0002 - Company 2
0003 - AT&T

ooops AT&T put on Query String . Great !

What happens with the queryString (a NameValueCollection ) ? If we were to pass only 0003 - AT&T the query string would be composed of:

• Key1 with valye "003 - AT" and
• another entry with the key nll and the value "T"
  

Now come back to the piece of code above. What happens if requestParameterName is null ? When requestParameterName is null (for some stupid key missing in an XML file), the request would still read the value of the key null.
But now, context.Request[requestParameterName] returns, waw, "T".
Creating a GUID from the string "T" is pretty difficult isn't it ?

That's a sample of how nice programming is :)

Enjoy programming !