var howChecked = ""
for(i=1;i<4;i++)
{
var o = document.getElementsByName("R"+i)
var isChecked=false
for(j=0;j<o.length;j++)
{
if(o[j].checked) isChecked=true
}
if(isChecked)
howChecked +=","
}
if(howChecked.length<3) alert("没有全选")
alert("选了"+howChecked.length + "个")
for(i=1;i<4;i++)
{
var o = document.getElementsByName("R"+i)
var isChecked=false
for(j=0;j<o.length;j++)
{
if(o[j].checked) isChecked=true
}
if(isChecked)
howChecked +=","
}
if(howChecked.length<3) alert("没有全选")
alert("选了"+howChecked.length + "个")
var scopeNum = 0
var howChecked = ""
for(i=1;i<4;i++)
{
var o = document.getElementsByName("R"+i)
var isChecked=false
for(j=0;j<o.length;j++)
{
if(o[j].checked)
{
isChecked=true
//如果有分值可以这样坐scopeNum+=parseInt(o[j].value)
}
}
if(isChecked)
howChecked +=","
}
if(howChecked.length<3) alert("没有全选")
alert("选了"+howChecked.length + "个")
cNum=0;
</script>
<input type="checkbox" name="tt">
<input type="checkbox" name="tt">
<script for="tt" event="onclick">
if(this.checked==true)
{
++cNum;
}
else
{
--cNum;
}
</script>
<input type="button" onclick="right()">
<script>
function right()
{
var tt = document.getElementsByName("tt").length;
if(cNum<tt)
{
alert('选不全');
}
}