js中怎么使点击按钮后文本框获得焦点?
<script language="javascript">
function setFocus()
{
var obj = event.srcElement;
var txt =obj.createTextRange();
txt.moveStart('character',obj.value.length);
txt.collapse(true);
txt.select();
}
</script>
<input type="text" value="abcdefg123456789" onfocus="setFocus()">
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.0 Transitional//EN">
<HTML>
<HEAD>
<TITLE> New Document </TITLE>
<META NAME="Generator" CONTENT="EditPlus">
<META NAME="Author" CONTENT="">
<META NAME="Keywords" CONTENT="">
<META NAME="Description" CONTENT="">
<SCRIPT LANGUAGE="JavaScript">