Jqgrid Selectable Headers

I've a huge field list in a table in which I need to populate as a headers of JQgrid. All these headers need t开发者_StackOverflowo be in the form of a select box (dropdown list)? How can I achieve this through JQgrid?

Thank You Sai Krishna

UPDATED:

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I've added the image with dropdown headers in the following image JQgrid headers