On php page in a form, One combo box has list of my Customer from mysql table customer. Another combo box has invoiceno stored in invoice table which has respective customer records. I want to select customer from first combo box and filter invoiceno from the second one according to the first one for the respective customer. Any one help me for php or java or both codings? Means if I select customer1 then in the second combo box should show all invoiceno respective to the custermer1.