SQL Parameter And Item Has Already Been Added. Key In Dictionary: Error

Hi there,





I have a search page that redirects to another page transfering the search terms in a querystring. In the page to display the search results I use SQL parameters to show the results. Everything runs fine until I do a page refresh or use paging to bring up another set of results.





Everytime I try to refresh/page etc. I get the following error:





Item has already been added. Key in dictionary: "@CityTown" Key being added: "@CityTown"


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.ArgumentException: Item has already been added. Key in dictionary: "@CityTown" Key being added: "@CityTown"





Source Error:








Line 20:


Line 21: 'Creates parameters for the WHERE statement taking the querystring contents from previous page


Line 22: dsPropertyListing.Parameters.Add("@CityTown", CityTown)


Line 23: dsPropertyListing.Parameters.Add("@Suburb", Suburb)


Line 24: dsPropertyListing.Parameters.Add("@Rooms", Rooms)








Source File: K:detailsdetailspropertylisting.aspx Line: 22





Stack Trace:








[ArgumentException: Item has already been added. Key in dictionary: "@CityTown" Key being added: "@CityTown"]


System.Collections.Hashtable.Insert(Object key, Object nvalue, Boolean add) +931


System.Collections.Hashtable.Add(Object key, Object value) +11


ASP.detailspropertylisting_aspx.Page_Load(Object sender, EventArgs e) in K:detailsdetailspropertylisting.aspx:22


System.EventHandler.Invoke(Object sender, EventArgs e) +0


System.Web.UI.Control.OnLoad(EventArgs e) +55


System.Web.UI.Control.LoadRecursive() +27


System.Web.UI.Page.ProcessRequestMain() +731








Any sugestions that anyone could provide would be greatly appreciated. This error obviously renders the search features useless.





Thanks in anticipation,





TCM