Executing procedure/functions in child form from MDI form - Question repeating with more clarification

Sir,

I have one MDI form and 20 child forms.  In each child form I have command button named cmd_add.  According requirement, in each form, procedure/function coming under click event of cmd_add is different.  I have one command button in MDI form.  when I will click command button in MDI form, I want to execute procedure/function written under the cmd_add command button of active child form.  if I give msgbox inside procedure or function in child form, it is executing, but other satement are not executing or negleting. I hope, now question is clear.  Please help me.