（。btnprint）。click（function（）{

var value =

(".btnprint").click(function () { var value =

（。txtln）。val（）;

(".txtln").val();

（＃lblln）。html（value ）;
返回false;
}）;

("#lblln").html(value); return false; });

<asp:TextBox ID="TextBox_ln" runat="server" CssClass="txtln TextBox screenOnly"></asp:TextBox>
<asp:Label ID="lblln" ClientIDMode="Static" runat="server" Text=""></asp:Label>

<asp:ImageButton ID="btn_print" runat="server" Text="Print" OnClientClick="javascript : window.print();"
           OnClick="Button4_Click1" OnPreRender="btn_print_PreRender" CssClass="btnprint btn screenOnly"
           Style="margin-right: 30px; margin-top: 20px;" ImageUrl="~/images/print.png" OnUnload="btn_print_Unload"
           OnInit="btn_print_Init" OnLoad="btn_print_Load" />

代码落后：

code behind :

protected void Button4_Click1(object sender, EventArgs e)
       {
           ClientScript.RegisterStartupScript(this.GetType(), "PrintOperation", "printing()", true);
       }