I have a '96 dodge dakota, my door is acting up and the handle is not working correctally, i need a new part for the handle. Please help!

 

What exactly is happening? Is it not catching? Does it work sometimes, or never? Is the problem inside the door? or is it simply the handle?

 

im not 100% sure, but i took it out, and it was filled with rust. I have sone deruster that took off most of the rust, and i reinstalled it and greased it, but it is still feels like it is catching on something. please help!