复选框全选

function selectAllCheckbox() {
if(null == document.forms[0].m_selectedRow){
document.forms[0].selectAll.checked = false;

}
else {
var index = document.forms[0].m_selectedRow.length;
if(undefined == index && document.forms[0].m_selectedRow.disabled == false){
document.forms[0].m_selectedRow.checked = document.forms[0].selectAll.checked;
}
else{
for(var i = 0;i<index;i++){
if(document.forms[0].m_selectedRow[i].disabled == false){
document.forms[0].m_selectedRow[i].checked = document.forms[0].selectAll.checked;
}
}
}
checkAllCheckBox();
}

}

function checkAllCheckBox() {
var index = document.forms[0].m_selectedRow.length;
var counter = 0;
var compareCounter = 0;
if(undefined == index){
if(document.forms[0].m_selectedRow.checked == true){
counter++;
}
compareCounter++;
}else{
for(var i = 0;i<index;i++){
if(document.forms[0].m_selectedRow[i].checked == true){
counter++;
}
compareCounter++;
}
}
if(counter == compareCounter && compareCounter!=0){
document.forms[0].selectAll.checked = true;
}else{
document.forms[0].selectAll.checked = false;
}
}