var isChecked = true;
function SetAllCheckBoxes()
{
    var form = document.getElementById('partlist');
    var button = document.getElementById('selectButton');
    
    //var boxCount = form.elements.getparts[].length;
    
    for(var i = 0; i < form.elements.length; i++){
        if(form.elements[i].name == 'getparts[]'){
            form.elements[i].checked = isChecked;
        }
    }
        
    if(isChecked){
        isChecked = false;
        button.value = "Clear All"
    }else{
        isChecked = true;
        button.value = "Select All";
    }
}