I seems that you are providing right arguments in fspecial function. You have to specify the number of columns and rows in this function. I copied the below lines from matlab help:
h = fspecial('average', hsize) returns an averaging filter h of size hsize. The argument hsize can be a vector specifying the number of rows and columns in h, or it can be a scalar, in which case h is a square matrix. The default value for hsize is [3 3].
gaus = fspecial('gaussian', [M N],5,0.7);
You can find more about it here: http://www.mathworks.se/help/images/ref/fspecial.html