Health Bar Help

[30quickdead (30quıckdead)]

So i am making a health system and i am on the widget part, i made a widget with progress bar and uploaded two images in to it but its not working how i had in mind

When i change the percent all of the image changes but i only want the bar to change.
I made two images with one is empty and the other one is filled how can i make it only change the red part in the middle

[30quickdead (30quıckdead)]

I made it!

Changed the images i upload like this and change the fill image with the second one and it works just like i had in my mind