how to Rewrite url again

hi

i have many link below like :

<a href="Default.aspx?id=1" >link1</a>

<a href="Default.aspx?id=2" >link2</a>

i want show below like :

http://www.mySite.com/Category/1/linke1.html

http://www.mySite.com/Category/2/linke2.html

please help me

thanks