try
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<input name="checkbox1" type="checkbox" value="a" />
<input name="checkbox2" type="checkbox" value="a" />
<input name="checkbox3" type="checkbox" value="a" />
<input name="checkbox4" type="checkbox" value="a" />1个按钮
<input type="button" name="Submit2" value="" onclick="aa();"/>
<script language="javascript">function aa(){
if(check()){
alert("全部都选了");
}
else{
alert("没有全选");
}
}function check(){
for(var i=1;i<=4;i++){
var obj = document.getElementsByName("checkbox"+i)[0];
if(!obj.checked)
return false;
}
return true;
}
</script>
------------------------------------------------------
<input name="checkbox1" type="checkbox" value="a" />
<input name="checkbox2" type="checkbox" value="a" />
<input name="checkbox3" type="checkbox" value="a" />
<input name="checkbox4" type="checkbox" value="a" />1个按钮
<input type="button" name="Submit2" value="" onclick="aa();"/>
<script language="javascript">function aa(){
if(check()){
alert("全部都选了");
}
else{
alert("没有全选");
}
}function check(){
for(var i=1;i<=4;i++){
var obj = document.getElementsByName("checkbox"+i)[0];
if(!obj.checked)
return false;
}
return true;
}
</script>
<head>
<script type="text/javascript">
function checkIt(){
if(!document.all.checkbox1.checked){
alert("1error");
document.all.checkbox1.checked = true;
}if(!document.all.checkbox2.checked){
alert("2error");
document.all.checkbox2.checked = true;
}if(!document.all.checkbox3.checked){
alert("3error");
document.all.checkbox3.checked = true;
}if(!document.all.checkbox4.checked){
alert("4error");
document.all.checkbox4.checked = true;
}
}
</script>
</head><body>
<input name="checkbox1" type="checkbox" />
<input name="checkbox2" type="checkbox" />
<input name="checkbox3" type="checkbox" />
<input name="checkbox4" type="checkbox" /> <input type="button" name="Submit2" value="" onclick="checkIt();"/>
</body>
</html>
---------------------------------------------------------
<input name="cb" type="checkbox" value="a" />
<input name="cb" type="checkbox" value="a" />
<input name="cb" type="checkbox" value="a" />
<input name="cb" type="checkbox" value="a" />1个按钮
<input type="button" name="Submit2" value="验证一下" onclick="aa();"/>
<script language="javascript">function aa(){
if(check()){
alert("全部都选了");
}
else{
alert("没有全选");
}
}function check(){
var obj = document.getElementsByName("cb");
for(var i=0;i<obj.length;i++){
if(!obj[i].checked)
return false;
}
return true;
}
</script>
你新建一个空的HTML文件,把我上面的代码复制进去,到浏览器打开,看能不能验是否全选了