全选、全不选和反选
<!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>
<meta http-equiv="Content-Type" content="text/html; charset=utf-8" />
<title>全选反选</title>
</head>
<body>
<input id="btn1" type="button" value="全选" />
<input id="btn2" type="button" value="不选" />
<input id="btn3" type="button" value="反选" /><br><br>
<div id="div1">
<input type="checkbox" /><br>
<input type="checkbox" /><br>
<input type="checkbox" /><br>
<input type="checkbox" /><br>
<input type="checkbox" /><br>
<input type="checkbox" /><br>
<input type="checkbox" /><br>
<input type="checkbox" /><br>
<input type="checkbox" /><br>
</div>
</body>
</html>
<script>
var oBtn1=document.getElementById('btn1');
var oBtn2=document.getElementById('btn2');
var oBtn3=document.getElementById('btn3');
var oDiv=document.getElementById('div1');
var allCheckbox=oDiv.getElementsByTagName('input');
oBtn1.onclick=function(){
for (var i=0;i<allCheckbox.length;i++){
allCheckbox[i].checked=true;
}
};
oBtn2.onclick=function(){
for (var i=0;i<allCheckbox.length;i++){
allCheckbox[i].checked=false;
}
};
oBtn3.onclick=function(){
for (var i=0;i<allCheckbox.length;i++){
if(allCheckbox[i].checked==true){
allCheckbox[i].checked=false;
}else{
allCheckbox[i].checked=true;
}
}
};
</script>
