Implement an example of two text boxes simultaneous input

Examples are as follows:

<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http:///TR/xhtml1/DTD/">
<html xmlns="http:///1999/xhtml" lang="zh-CN">
<head>
<meta http-equiv="Content-Type" content="text/html; charset=gb2312" />
<title></title>
</head>
<body>
<script language="javascript">
function copyob1toob2(){
  ["ob_text_2"].value=["ob_text_1"].value
}
</script>
<input type="text"  size=20 onkeyup="copyob1toob2()">
<input type="text"  size=20>

</body>
</html>

The above example of implementing the simultaneous input of two text boxes is all the content I share with you. I hope you can give you a reference and I hope you can support me more.