checkbox的全选和反选

<meta charset=gb2312> 

<script language="javascript"> 

function selectAll() 

{ 

for(var i=0;i<document.form1.range.length;i++) 

{ 

document.form1.range[i].checked=true; 

} 

} 

function unSelect() 

{ 

for(var i=0;i<document.form1.range.length;i++) 

{ 

if(document.form1.range[i].checked) 

{ 

document.form1.range[i].checked=false; 

} 

else 

{ 

document.form1.range[i].checked=true; 

} 

} 

} 

</script> 

<form name="form1" id="form1"> 

<input type="checkbox" value="1" name="range">1<br> 

<input type="checkbox" value="2" name="range">2<br> 

<input type="checkbox" value="3" name="range">3<br> 

<input type="checkbox" value="4" name="range">4<br> 

<input type="checkbox" value="5" name="range">5<br> 

<input type="button" value="全选" onclick="selectAll();"> 

<input type="button" value="反选" onclick="unSelect();"> 

</form>