Submit button is not working in workflow in Enterprise Portal

For submission i have to press submit button in Ax core then it’s submitted.

Suppose user1 initiated the workflow in core then user2 logged in EP and here he is able to see Approve or reject menu in Action tin worlflow yellow toolbar in EP.

But for submission in EP nothing is happening ? Why ?

check the belove link.

http://msdn.microsoft.com/en-us/library/ee677503(v=ax.50).aspx