how to remove the short lines(horizontal lines) before the menu

how to remove the short lines(horizontal lines) before the menu

I created a header Navigation using images. I have separate images for all
the menus. But my problem is Some short lines appears before my each image
menu. I dont know why. I checked with the images but nothing wrong with
the images. I will paste my image screenshort please have a look at it and
tell me what i have to do to remove the short (horizontal line)
!file:///home/oomsys/Desktop/July%20Report/short.png