$(document).ready(function(){
	
	//Make copy of initial values
	var initialArray = new Array();
	
	$("#cf2_field_7 option").each(function(){
	
		initialArray.push($(this).attr('value'));
		
	});
	
	//Detect change event
	$("#cf2_field_6").change(function(){
		
		var option = $(this).val();
		var newHTML = '';
		
		var strChecker = option.substring(0,4);
		
		$.each(initialArray, function(key, value) { 
			
			if (value.substring(0,4) == strChecker) {
				
				newHTML += '<option value="' + value + '">' + value + '</option>';
				
			}
			
			else if ( (value.substring(0,2) == 'VW') && (strChecker == 'VOLK') ) {
				
				newHTML += '<option value="' + value + '">' + value + '</option>';
			
			}
			else if ( (value.substring(0,3) == 'BMW') && (strChecker == 'BMW') ) {
				
				newHTML += '<option value="' + value + '">' + value + '</option>';
			
			}
			else if ( (value.substring(0,3) == 'L-R') && (strChecker == 'LAND') ) {
				
				newHTML += '<option value="' + value + '">' + value + '</option>';
			
			}
			
		});
		
		$("#cf2_field_7").html(newHTML);
		
								  
	});
	
						   
});

//Alfa: cf2_field_7