Not Getting String Functions Inside Expression

Hi All,

I want to call the string functions inside BizTalk expression shape.

I have created orchestration variable of string type varTemp and assigned it with some string value from property schema.

I want to use Substring function inside  expression shape like

varTemp.SubString(“some other string”);

The problem here is, I am not getting any string functions for varTemp inside an expression shape, even I tried with Fully Qualified Name like System.String, but Not getting the complete string functions,

Please advice me to use the string functions inside expression shape.

Earlier I worked on 2006, now working on 2004.. Please let me know the whether intellisense support is provided in  2004 or not supported.