全选全不选

function selectAll() {
var obj = document.fom.elements;
for ( var i = 0; i < obj.length; i++) {
if (obj[i].name == "ids") {
obj[i].checked = true;
}
}

}

function unselectAll() {
var obj = document.fom.elements;
for ( var i = 0; i < obj.length; i++) {
if (obj[i].name == "ids") {
if (obj[i].checked == true)
obj[i].checked = false;
else
obj[i].checked = true;
}
}

}