function getElement(id_element)
{   
	if (document.getElementById)
        var returnVar = document.getElementById(id_element);
    else if (document.all)
        var returnVar = document.all[id_element];
    else if (document.layers)
        var returnVar = document.layers[id_element];
        
    return returnVar; 	
}

function set_element_value(id_element, value)
{
	var elem = getElement(id_element);
	elem.value = value;
	return false;
}

document.getElementsByClassName = function(cl) 
{
	var retnode = [];
	var myclass = new RegExp('\\b'+cl+'\\b');
	var elem = this.getElementsByTagName('*');
	
	for (var i = 0; i < elem.length; i++) 
	{
		var classes = elem[i].className;
		if (myclass.test(classes)) 
			retnode.push(elem[i]);
	}
	
	return retnode;
}; 

function clear_tree_background()
{
	var elems = document.getElementsByClassName("tree_item");
	
	for(var i = 0;i < elems.length;i++)
	{
		if(elems[i].style)
			elems[i].style.backgroundColor = 'white';
	}
}

function in_array(item, array)
{
	for(var i = 0; i < array.length; i++)
	{
	   if(array[i] == item)
	   	return true;
	}
	
	return false;
}