Check if record already exist using LINQ to sql

HI:
I'm using LINQ to sql with c#
I have a text box on a web page , after entering a value to that box
I need to validate whither if this value exist in myTable or not

Var xmyTable = (from ymyTable in objDataContext.myTables
                              Select new 
                             {
                               ymyTable.myCode
                              ymyTable.myNmae
                             }

Select allOpen in new window

please help