how to make sum value changed depend on select box?

i have a multiple HTML select element

        
                      

              相关标签:
       
      
      
      

        

          
回答
         

        

                         				            
                               
         
消灭零回复
 
                 
        
        

          

            
            

              
              

            
    


                                 
              
            
                          
    

        
         

                验证码