JSでドロップダウンリストの連動を実現します.

	
		
		
	
	
		
  ：
			
				   
				  
				  
				  
			
		
		
  ：
			
				   
			
		
	
	

//             
var data = [
	["  ","  ","  "],
	["  ","  ","   "],
	["  ","    ","   "]
]

function change(){
	var area = document.getElementById("area");
	var countrys = document.getElementById("country");
	var index = area.value;					
	var selects = data[index-1];			//         value     
	
	var oldOptions = countrys.children;		// children，          (   )
	var length = oldOptions.length;			//！！  ，    length  ：
											//            length， length    ，     。
	for(var i=0;i