谢谢楼上两位。
都试过了,不好使啊。
把代码贴上来,大家看看有何高招。
<SCRIPT TYPE="text/JavaScript">
function fnOnLoad()
{
        document.form1.btndisabled.disabled=true;  //怎样让确定两个字显示成红色???
        return;
}
function cfnKeyDown(strPreFocus,strNextFocus)
{
    //37is←
    //38is↑
    //39is→
    //40is↓
    if (this.event.keyCode == 37 || this.event.keyCode == 38){
        if (strPreFocus != ""){
            if (document.form1.elements[strPreFocus].name=="KEY_MISENO"){
                document.form1.elements[strPreFocus].select();  //怎样实现输入的内容被选中???
            }else{
                document.form1.elements[strPreFocus].focus();
            }
        }
    }
    if (this.event.keyCode == 39 || this.event.keyCode == 40){
        if (strNextFocus != ""){
            if (document.form1.elements[strNextFocus].name=="KEY_MISENO"){
                document.form1.elements[strNextFocus].select();  //怎样实现输入的内容被选中???
            }else{
                document.form1.elements[strNextFocus].focus();
            }
        }
    }
    return;
}
</script>
</HEAD>
<base target="_self">
<BODY BGCOLOR="#529488" onLoad="fnOnLoad();">
    <FORM method="post" name="form1" onSubmit="return (false);" >
        <INPUT name="KEY_MISENO" type="text" size="6" maxlength="6" value="" onKeyDown="cfnKeyDown('','btnCommit')">
        <br>
        <INPUT TYPE="button" NAME="btnCommit" VALUE="確定" onKeyDown="cfnKeyDown('KEY_MISENO','btncancle');">
        <br>
        <INPUT TYPE="button" NAME="btncancle" VALUE="取消" onKeyDown="cfnKeyDown('btnCommit','');">
        <br>
        <INPUT TYPE="button" NAME="btndisabled" VALUE="不可用"  style="color:red">
    </FORM>
</BODY>
</HTML>