ruby on rails - Passing local variable into partial returns NameError -

i trying pass index of partial , getting nameerror.

right now, render statement , able access builder fine.

<%= render 'my_partial', :builder => form_helper %>

but when adding index below, error.

<%= render 'my_partial', :builder => form_helper, :locals => {:index => index } %>

any thoughts? thanks!

edit:

while trying

<%= render :partial => 'my_partial', :locals => {:builder => form_helper, :index => index } %>

the specific error "undefined local variable or method `index' #<#:0x007fc37206ae40>"

either:

 <%= render 'my_partial', :builder => form_helper, :index => index %>

or:

<%= render :partial => 'my_partial', :locals => {:index => index, :builder => form_helper } %>

Bready