function MoveUp(combo_name)
{
	var combo=document.getElementById(combo_name);
	i=combo.selectedIndex;
	if (i>0)
	{
		swap(combo,i,i-1);
		combo.options[i-1].selected=true;
		combo.options[i].selected=false;
	}
}

function MoveDown(combo_name)
{
	var combo=document.getElementById(combo_name);
	i=combo.selectedIndex;

	if (i<combo.length-1 && i>-1)
	{
		swap(combo,i+1,i);
		combo.options[i+1].selected=true;
		combo.options[i].selected=false;
	}
}

//this function is used to swap between elements
function swap(combo,index1, index2)
{
	var savedValue=combo.options[index1].value;
	var savedText=combo.options[index1].text;

	combo.options[index1].value=combo.options[index2].value;
	combo.options[index1].text=combo.options[index2].text;

	combo.options[index2].value=savedValue;
	combo.options[index2].text=savedText;
}

function MoveToTop(combo_name)
{
	var combo=document.getElementById(combo_name);
	i=combo.selectedIndex;
	
	for (;i>0;i--)
	{
		swap(combo,i,i-1);
		combo.options[i-1].selected=true;
		combo.options[i].selected=false;
	}
}

function MoveToBottom(combo_name)
{
	var combo=document.getElementById(combo_name);
	i=combo.selectedIndex;
	
	if (i>-1)
	{
		for (;i<combo.length-1;i++)
		{
			swap(combo,i+1,i);
			combo.options[i+1].selected=true;
			combo.options[i].selected=false;
		}
	}
}

//moves options from one selection box (combo box) to another
//removes the all selected options from one combo box and adds them to the second combo box
function MoveElements(FromComboName,ToComboName)
{
	var FromCombo=document.getElementById(FromComboName);
	var ToCombo=document.getElementById(ToComboName);

	var to_remove_counter=0; //number of options that were removed (num selected options)

	//move selected options to right select box (to)
	for (var i=0;i<FromCombo.options.length;i++)
	{
		if (FromCombo.options[i].selected==true)
		{
			var addtext=FromCombo.options[i].text;
			var addvalue=FromCombo.options[i].value;
			ToCombo.options[ToCombo.options.length]=new Option(addtext,addvalue);
			FromCombo.options[i].selected=false;
			++to_remove_counter;
		}
		else
		{
			FromCombo.options[i-to_remove_counter].selected=false;
			FromCombo.options[i-to_remove_counter].text=FromCombo.options[i].text;
			FromCombo.options[i-to_remove_counter].value=FromCombo.options[i].value;
		}
	}

	//now cleanup the last remaining options 
	var numToLeave=FromCombo.options.length-to_remove_counter;
	for (i=FromCombo.options.length-1;i>=numToLeave;i--) 
	{ 
		FromCombo.options[i]=null;
	}
}

function toggleSelectAll(combo_name)
{
	
	var select_all_link=document.getElementById('select_all_link');
	var combo=document.getElementById(combo_name);//get the select

	var to_select=true;
	var select_link_new_caption;//the new "Select All" link caption will be here
	if (select_all_link.unselectAll==true)//this is a new attribute that is dynamically added
	{
		//we now want to select all options
		to_select=false;
		select_all_link.unselectAll=false;
		select_link_new_caption="Select All";//set the new caption
	}
	else
	{
		//we now want to unselect all options
		select_all_link.unselectAll=true;
		select_link_new_caption="Unselect All";//set the new caption
	}

	select_all_link.innerText=select_link_new_caption;//change the caption of the select all link
	SelectAll(combo,to_select);
}

//select is true for selecting all, false for unselecting all
function SelectAll(combo,select)
{
	for (var i=0;i<combo.options.length;i++)
	{
		combo.options[i].selected=select;
	}
}