rails: pass value of a text field to a helper function

I'm sure this is a basic question... I have a nested form where the nested object contains a text field. There is a link_to_function in the form that calls some javascript. I want to pass the ja开发者_运维问答vascript function the value of a hidden field in the form (image_type_id).

Can I reference this with some ruby or does this need javascript?

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Pass this (or this.parent, depending on where your link is on the form) and use jQuery on the Javascript side to get the hidden value.