I  have a list called departments in coulmn dept . 

another list called approvers , fields are dept is lookup column from department list and email id is another column. 

Now i have a form where in field department will be filled by the user and the approvers based on the dept i want to populate the email ids off under that dept.

I used calculated value in the form and used the 

below formula 

lookup("Approvers List","Dept",Departments,"EMail ID",true)

Now the question is how i can connect to mail list column. Please help me

Thanks

Yogesh