function test(obj)
{
}<form name="test1" onsubmit="test(this)">
</form>
<form name="test2" onsubmit="test(this)">
</form>
{
}<form name="test1" onsubmit="test(this)">
</form>
<form name="test2" onsubmit="test(this)">
</form>
function test(x) {
var obj=eval(x.name);
obj.txt.value="fadsfassafasfasdf";
// obj.submit(); //这句放开就可以提交当前表单
}<form name="test1" action="#">
<input type="text" name="txt">
<input type="button" onClick="test(form)" value="提交">
</form><form name="test2" onsubmit="test(this)">
<input type="text" name="txt">
<input type="button" onClick="test(form)" value="提交">
</form>