var key;

function alertkey(e) {
	if( !e ) {
		if( window.event ) {
			e = window.event;
		} else {
			return;
		}
	}
	if( typeof( e.keyCode ) == 'number'  ) {
		//DOM
		e = e.keyCode;
	} else if( typeof( e.which ) == 'number' ) {
		//NS 4 compatible
		e = e.which;
	} else if( typeof( e.charCode ) == 'number'  ) {
		//also NS 6+, Mozilla 0.9+
		e = e.charCode;
	} else {
		return;
	}
	//window.alert('The key pressed has keycode ' + e + ' and is key ' + String.fromCharCode( e ) );
	key = e;
}		

function nextOrBack(obj,num)
{
	if(key == 8)
	{
		num--;
		if(num < 1)
			num = 5;
	}
	else
	{
		num++;
		if(num > 5)
			num = 1;
	}
	document.getElementById("plate_num_" + num).focus();
	document.getElementById("plate_num_" + num).select();
}

function getPlate()
{
	
	var plate = "";
	i=1;
	while(document.getElementById("plate_num_" + i))
	{
		
		plate += document.getElementById("plate_num_" + i).value;
		i++;
		if(i>5)
			break;
	}
	
	var patt1 = /\D/g; 
	var result = plate.match(patt1);
	
	if(result != null)
	{
		document.getElementById("answer_overlay").style.display = "block";
		document.getElementById("plate_check_result").style.display = "none";
		document.getElementById("plate_check_result2").style.display = "none";
		document.getElementById("plate_check_result3").style.display = "block";
	}
	else
		checkPlateAv(plate);
}