String.prototype.trim = function() { return this.replace(/^\s+|\s+$/g, ''); }

Array.prototype.exists = function(value) {
    var i;
    var length = this.length;
    for (var i = 0; i < length; i++) 
    {
        if (this[i] == value) 
            return true;
    }
    return false;
};


function $(id)
{
    try
    {
        return document.getElementById(id);
    }
    catch(e)
    {
        alert(e);
    }
    return null;
}

function SelectAllCheckBoxes(mas, status)
{
    var i = 0; var str = "";
    for (i =0 ; i < mas.length; i++)
	{
		var obj = $(mas[i]);
		if (obj != null)
		{
			obj.checked = status;
		}
	}
}

function CountChecked(mas)
{
	var i = 0;
    var counter = 0;
    var length = mas.length
    for (i = 0; i < length; i++)
	{
		var obj = $(mas[i]);
		if (obj != null && obj.checked)
		{
			counter++;
		}
	}
	return counter;
}

function GetIndexesForChecked(mas)
{
	var i = 0;
    var length = mas.length
    var result = new Array();
    for (i = 0; i < length; i++)
	{
		var obj = $(mas[i]);
		if (obj != null && obj.checked)
		{
			result.push(i);
		}
	}
	return result;
}

// 1 - checked all
// 0 - none checked
function CheckedState(mas)
{
    var i = 0;
    var counter = 0;
    var length = mas.length
    for (i = 0; i < length; i++)
	{
		var obj = $(mas[i]);
		if (obj != null && obj.checked)
		{
			counter++;
		}
	}
	if (counter == length)
	{
	    return 1;
	}
	else if (counter == 0)
	{
	    return 0;
	}
	return -1;
}

function IsCheckedAll(mas) {
    return CheckedState(mas) == 1;
}