Unless I put pecans in my chocolate chip cookies they always fall flat when I take them out of the oven.  What do I need to do for them to stand up. 
Maybe you need to buy a new box of baking soda or baking powder? Baking soda & baking powder can & do lose 'oomph' over time.  Otherwise try chilling the dough for at least 4 hours before baking. Chilling the dough usually helps butter/shortening based cookies hold their form a tad bit better. 