ajax/应用1

   //init_xmlhttp函数会根据不同的浏览器初始化xmlhttp对象 
         function init_xmlhttp()
         {
               var A=null; 
               try 
               { 
                    A=new ActiveXObject("Msxml2.XMLHTTP"); //IE 
               } 
               catch(e) 
               { 
                   try 
                   { 
                         A=new ActiveXObject("Microsoft.XMLHTTP"); //非IE
                   } 
                   catch(oc) 
                   { 
                         A=null 
                   } 
               }
               
               if ( !A && typeof XMLHttpRequest != "undefined" ) 
               { 
                    A=new XMLHttpRequest() 
               } 
              return A 
         }

      
        function Go(obj) 
        { 
            
              var var1 = document.form1.ddl_1[document.form1.ddl_1.selectedIndex].value;
              if((var1 == "7")||(var1 == "5")) //5核销人 7 支付方式
              {
                    //得到选择框的下拉列表的value 
                    var svalue = obj.value;   
//                    alert(svalue);return false;
                    //定义要处理数据的页面 
                    var weburl = "select_data_ysfhxcx.aspx?list_item_value="+svalue;    
                    //初始化个xmlhttp对象 
                    var xmlhttp = init_xmlhttp(); 
                    
                    //去weburl获取数据，第一个参数最好为get，第三个参数最好为true 
                    xmlhttp.open("get",weburl,true); 
//                    alert("a"); return false;//执行了
                    xmlhttp.onreadystatechange=function() 
                    {
//                        alert(xmlhttp.readyState); return false;//这时接到的值为1，不知是什么意思，可能表示开始执行，在select_data_ysdzd.aspx中就能断到断点
                        if(xmlhttp.readyState == 4)//4代表成功返回数据 
                        {
                            var result = xmlhttp.responseText;//得到服务器返回的数据
                            document.getElementById("txt_of_pnl1").style.display = "none";
                            document.getElementById("ddl_of_pnl1").style.display="";
                            document.getElementById("ddl_of_pnl1").length = 0;                                           
                            document.getElementById("ddl_of_pnl1").options.add(new Option(" "," ")); 
                            if(result != "")//如果返回的数据不是空 
                            {
//                               alert(result);return false;
                                 var allArray = result.split(",");
                                 //循环这个数组，注意是从1开始，因为收到的字符串第一个字符是，号，所以分割后第一个数组为空 
                                 for(var i=1;i<allArray.length;i++) 
                                 {
                                    var thisArray = allArray[i].split("|");
                                    document.getElementById("ddl_of_pnl1").options.add(new Option(thisArray[0].toString(),thisArray[1].toString())); 
                                 }
                            }
                            else
                            {
                                document.getElementById("ddl_of_pnl1").length = 0; 
                            }
                        }
                        
                    }
                     xmlhttp.send(null); //没有这句，根本进不到select_data_ysdzd.aspx页面！！！！！     
              }//if((var1 == "7")||(var1 == "5"))   End
              else
              {
                   document.getElementById("txt_of_pnl1").style.display = "";
                   
                   document.getElementById("ddl_of_pnl1").style.display = "none";
              }
        }

CS:

  ddl_1.Attributes.Add("onchange", "Go(this)");//最左边的按钮"各种检索条件"
        this.ddl_of_pnl1.Attributes.Add("onchange", "javascript:document.form1.hid_ddl_right.value=this.value;");//右边panel中的DDL

HTML:

 <td>
        <asp:DropDownList ID="ddl_1" runat="server" Width="140px">
            <asp:ListItem Text="" Value="0"></asp:ListItem>
            <asp:ListItem Text="编号" Value="1"></asp:ListItem>            
            <asp:ListItem Text="单号" Value="2"></asp:ListItem>            
            <asp:ListItem Text="凭证号" Value="3"></asp:ListItem>
            <asp:ListItem Text="支票号" Value="4"></asp:ListItem>            
            <asp:ListItem Text="核销人" Value="5"></asp:ListItem>
            <asp:ListItem Text="涉帐单位" Value="6"></asp:ListItem>
            <asp:ListItem Text="支付方式" Value="7"></asp:ListItem>
        </asp:DropDownList>
    </td>
    <td>        
        <asp:Panel ID="pnl1" runat="server" Width="100px" >
            <asp:TextBox ID="txt_of_pnl1" runat="server" Width="140px" CssClass="input_text"></asp:TextBox>
            <asp:DropDownList ID="ddl_of_pnl1" style="display:none;" runat="server"   Width="140px">
                                </asp:DropDownList>
        </asp:Panel>
    </td>