How to preserve the history page: IFRAME page apply

    Retention History Page Implementation method: IFRAME page apply   One, parent page Setup 1, aspx page (1) Add JavaScript function <script language= " JavaScript "type=" Text/javascript >   //Setting IFRAME    function Showlayer ()    { & nbsp;  document.all.myformlayer.style.display= ';     document.all.parentformlayer.style.height=0;     return false;   } </script>   (2) include existing pages in Div, under form, note that this part of the control must not set the Height property <div id= "Parentformlayer" runat= "Server" > ... </div>   (3) New Div and IFrame         < for displaying subordinate subpages Div id= "Myformlayer" runat= "Server" visible= "false" >              <iframe scrolling= "no" frameborder= "0" width= "100%" height=800 id= "IFRAME1" runat= "Server" >  & nbsp;          </iframe>          </div>   2, Aspx.cs code (1) Add squareMethod     public static void Createscript (System.Web.UI.Page mypage, String strscript, string ID)      {        string strscript = "<script language= ' JavaScript ' >";  & nbsp;      Strscript + = Strscript;         Strscript + = "</script>";           ClientScriptManager CSM = mypage. ClientScript;           if (!CSM. IsStartupScriptRegistered (ID))         {             CSM. RegisterStartupScript (MyPage. GetType (), ID, strscript);        }    }   (2) Add code in Event of link button          myformlayer.visible = true;         IFRAME1. Attributes.Add ("src", "p2w4.aspx");//P2w4 for the jump page, you can add parameters        Createscript (Page, "Showlayer ();", "show");   (3) Add code//clear IFRAME1 properties to the Page_Load () event to avoid events raised by other keystrokes with the page defined by SRC         IFRAME1. attributes["src"] = null;   II, sub-page settings 1, aspx page: no special settings.   2, Aspx.cs code (1) adds Code Response.Write ("<script>parent") to the event that returns the key. MyFormLayer.style.display = ' None ';</script> ');