给t1加上onchange事件
if (document.getElementById("t1").value!=""){
document.getElementById("t2").readonly=false;
}
if (document.getElementById("t1").value!=""){
document.getElementById("t2").readonly=false;
}
调试欢乐多
<html xmlns="http://www.w3.org/1999/xhtml">
<head>
<meta http-equiv="Content-Type" content="text/html; charset=utf-8" />
<title>无标题文档</title>
<script language="javascript">function $(object_ID)
{
return document.getElementById(object_ID);
}function setInput()
{
if($("t1").value == "")
{
$("t2").disabled = true;
}
else
{
$("t2").disabled = false;
}
}</script>
</head><body>
<input name="t1" type="text" id="t1" onblur="javascript:setInput()">
<input name="t2" type="text" id="t2" onfocus="javascript:setInput()" disabled> </body>
</html>
function xx
{
if(document.getElementById("t1").value!=null)
t2.readonly=false;
}
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml">
<head>
<script>
function check(){
if(document.getElementById('t1').value.length>0){
document.getElementById('t2').disabled=false;
}
}
</script>
</head>
<body>
<input name="t1" type="text" id="t1" onfocus="document.getElementById('t2').disabled=true" onblur="check()">
<input name="t2" type="text" id="t2">
</body>
</html>
<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 name="t1" type="text" id="t1" onblur="if(this.value.length>0){document.all('T2').readOnly=false}else{document.all('T2').readOnly=true}"> <input name="t2" type="text" id="t2" readonly="readonly">
</form>
</BODY>
</HTML>
<html xmlns="http://www.w3.org/1999/xhtml">
<head>
<script>
function check(){
if(document.getElementById('t1').value.length>0){
document.getElementById('t2').disabled=false;
}
if (document.getElementById('t2').value.length>0){
document.getElementById('t2').disabled=false;
}
}
</script>
</head>
<body>
<input name="t1" type="text" id="t1" onfocus="document.getElementById('t2').disabled=true" onblur="check()">
<input name="t2" type="text" id="t2" value="111">
</body>
</html>
<input name="t1" type="text" id="t1">
<input name="t2" type="text" id="t2">
可以这样子直接理解,t2在输入的时候t1必码有值存在,如果t1没有值存在t2则不可以输入。
<html xmlns="http://www.w3.org/1999/xhtml">
<head>
<meta http-equiv="Content-Type" content="text/html; charset=utf-8" />
<title>无标题文档</title>
<script language="javascript">function $(object_ID)
{
return document.getElementById(object_ID);
}function setInput()
{
if($("t1").value == "" && $("t2").value == "")
{
$("t2").disabled = true;
}
else
{
$("t2").disabled = false;
}
}</script>
</head><body>
<input name="t1" type="text" id="t1" onblur="javascript:setInput()">
<input name="t2" type="text" id="t2" onfocus="javascript:setInput()" disabled> </body>
</html>
<input type="text" id="t1" onblur="document.getElementById('t2').readOnly=this.value=='';"/>
<input type="text" id="t2" readonly="readonly"/>
<html>
<script type="text/javascript">
function setText(){
var t1 = document.getElementById("t1").value;
if(t1 != null && t1.length >= 1){
document.getElementById("t2").disabled=false;
}else{
document.getElementById("t2").disabled=true ;
}
}
</script><body>
<table>
<tr>
<td><input name="t1" type="text" id="t1" onchange="setText()"> </td>
<td><input name="t2" type="text" id="t2" disabled></td>
</tr>
</table>
</body>
</html>这样就可以啦 t1如果没有值 t2是不能输入