页面多form action解决方案

form里不能嵌套form，那样作所有form都将失效
<form   name= "form1 "   method= "post "   action= " ">
<input   type= "button "   value= "a "   onclick= "form1.action= 'a.asp ';form1.submit(); ">
<input   type= "button "   value= "b "   onclick= "form1.action= 'b.asp ';form1.submit(); ">
<input   type= "button "   value= "c "   onclick= "form1.action= 'c.asp ';form1.submit(); ">