problem merge verticies
 

hi
i'm having problems merging verticies, i know your supposed to select one vert then shift select the other, then the next thing to do is click merge verticies right!, however no matter what i do they just dont merge i tried messing with the merge settings but nothing happens, if anyone knows what i'm doing wrong please help

are the verts from the same polygon?

nother thing, take into consideration the size of your model, is it huge? then you need a huge merge distance.

Try Snapping to verticies, then merge.