function change_display(id)
{
	if(get_style(id, 'display')=='block') set_style(id, 'display', 'none');
	else set_style(id, 'display', 'block');
}

function set_display(val, id)
{
	if(val) set_style(id, 'display', 'block');
	else set_style(id, 'display', 'none');
}

function set_style(id, style, value)
{
	if(document.getElementById) document.getElementById(id).style[style]=value;
	else if(document.all) document.all[id].style[style]=value;
	else if(document.layers) document.layers[id].style[style]=value;
}

function get_style(id, style)
{
	if(document.getElementById) return document.getElementById(id).style[style];
	else if(document.all) return document.all[id].style[style];
	else if(document.layers) return document.layers[id].style[style];
}

function set_str(str, id)
{
	if(document.layers) document.layers[id].innerHTML=str;
	else if(document.all) document.all[id].innerHTML=str;
	else if(document.getElementById) document.getElementById(id).innerHTML=str;
}

function set_str_add(str, id)
{
	if(document.layers) document.layers[id].innerHTML+=str;
	else if(document.all) document.all[id].innerHTML+=str;
	else if(document.getElementById) document.getElementById(id).innerHTML+=str;
}

function exist_element(id)
{
	if(document.layers) return document.layers[id]?true:false;
	else if(document.all) return document.all[id]?true:false;
	else if(document.getElementById) return document.getElementById(id)?true:false;
}

function set_position(x, y, id)
{
	x=parseInt(x);
	y=parseInt(y);
	if(document.layers)
	{
		document.layers[id].style.left=x+'px';
		document.layers[id].style.top=y+'px';
	}
	else if(document.all)
	{
		document.all[id].style.left=x+'px';
		document.all[id].style.top=y+'px';
	}
	else if(document.getElementById)
	{
		document.getElementById(id).style.left=x+'px';
		document.getElementById(id).style.top=y+'px';
	}
}
function in_array(arr, el)
{
	var i=arr.length;
	for(c=0; c<i; c++) if(arr[c]==el) return true;
	return false;
}