Make sure you're filling @wages in the controller. Also, look into "collection_select", similar to the following, to replace your code in the view
<%= collection_select :pay, :wage_id, @wages, :id, :wage %>
HTH, Nathan
It looks like Gaurav's code has a join on the tables. i.e. <select name="infotantra[category_id]"> Probably not necessary, if I grab the id chosen and stick it into an instance variable.Then do and if / else.
Stuart