撤消和重做按钮为什么不能用
如题,其他按钮的功能都能实现就这两个特殊告诉下怎么用这两按钮.
<!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="">
</HEAD>
<BODY>
<form>
<input type="text">
<input type="reset" value="撤销" id="allback">
</form>
</BODY>
</HTML>
