Server Error in '/' Application.

Input string was not in a correct format.

Description: An unhandled exception occurred during the execution of the current web request. Please review the stack trace for more information about the error and where it originated in the code.

Exception Details: System.FormatException: Input string was not in a correct format.

Source Error:

Line 389:					
Line 390:					string control = "Controls/Tema/" + aktiftema + "/Home.ascx";
Line 391:					string sablon = db.Tekveri("Dosya","Select Dosya from sablon where Id=(Select Sablon from tur where Id="+Convert.ToInt32(Request.QueryString["Tur_Id"])+")");
Line 392:					 
Line 393:					if (File.Exists(Server.MapPath("/") + "Controls/Sablon/" + sablon +".ascx"))

Source File: d:\vhosts\btteknolojilinuxxx.com\vaxeelqor.shop\Default.aspx.cs Line: 391

Stack Trace:

[FormatException: Input string was not in a correct format.]
   System.Number.StringToNumber(String str, NumberStyles options, NumberBuffer& number, NumberFormatInfo info, Boolean parseDecimal) +13024119
   System.Number.ParseInt32(String s, NumberStyles style, NumberFormatInfo info) +122
   System.Convert.ToInt32(String value) +48
   Yonetim_Default.Page_Load(Object sender, EventArgs e) in d:\vhosts\btteknolojilinuxxx.com\vaxeelqor.shop\Default.aspx.cs:391
   System.Web.Util.CalliEventHandlerDelegateProxy.Callback(Object sender, EventArgs e) +52
   System.Web.UI.Control.OnLoad(EventArgs e) +97
   Yonetim_Default.OnLoad(EventArgs e) in d:\vhosts\btteknolojilinuxxx.com\vaxeelqor.shop\Default.aspx.cs:83
   System.Web.UI.Control.LoadRecursive() +61
   System.Web.UI.Page.ProcessRequestMain(Boolean includeStagesBeforeAsyncPoint, Boolean includeStagesAfterAsyncPoint) +693

Version Information: Microsoft .NET Framework Version:4.0.30319; ASP.NET Version:4.8.4797.0