# Changing the font size of the heading

I am writing a report (\documentclass[a4paper,12pt]{article}) which has an abstract in the beginning. I am using \usepackage{abstract} to write it. Then I am using \begin{abstract} ... \end{abstract} to put the abstract in the document. The problem is that the heading "Abstract" is at the same font size as the writing under it, only bold. I need to be able to control the size of this heading. Can anyone please help me.