function CreateString(str) 		 
    var obj = {                
         data: str,
         //trim 方法
         get trim() { 
             var newstr = [], i = 0, ch;
              for (var k = 0; k < this.data.length; k++) {                
                  if (str.charCodeAt(k) != 32) {
                      ch = str.substring(k);
                      break;
                  }                    
              }                   
              for (var j = ch.length - 1; j >= 0; j--) { 
                  if (ch.charCodeAt(j) != 32) {
                      newstr[i] = ch.substring(0, j + 1);                           
                      i++;
                      break;                        
                   }                    
              }                                      
               return newstr.join("");               
         }
    }                   
}