check whether a string contains a text in JavaScript? [duplicate]

This question already has an answer here:

• How to check whether a string contains a substring in JavaScript? 46 answers

How I can check whether a string contains a text in JavaScript? I have tried it with contain but not working.

 SuiteName= VarToString(Excel.Cells.Item(x, 1)); 
 ExecutionStatus= VarToString(Excel.Cells.Item(x, 3));

          if(ExecutionStatus.contain("yes"))
          {

            Log.Message("Need to execute this test case- "+ SuiteName)
          }