How to right click on a dropdownlist control and display a popup window?

I have a web page with a dropdownlist control which is populated by a method which reads thru a SQL table named PaymentTerms.  The dropdownlist is named ddlPaymentTerms.  I want to be able to right click on ddlPaymentTerms and then display my aspx page named MaintPaymentTerms.aspx.  This page already exist.  The part I don't know how to do is write the right click javascript function to display the popu window.  Can anyone help?


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