Problems accessing site master textbox value in another aspx form

I trying to access a textbox value from a aspx page from my site master but it doesn't seem to work and I get a "System.NullReferenceException: Object reference not set to an instance of an object." error. Appreciate any help given. Thanks!

In my site master code behind I am using the get accessor: Thing is if I hardcode my value for my get accessor return value, I will have no problem

public partial class SiteMaster : System.Web.UI.MasterPage

{ 
 public string Text
  { 
  get
  {
  return TextBox1.Text
  }
 }
}   

The aspx page which is trying to get the value from s开发者_如何学Goite master:

public partial class ProductSearch : System.Web.UI.Page
 {  
SiteMaster sm = new SiteMaster();

CommerceEntities db = new CommerceEntities();

protected void Page_Load(object sender, EventArgs e)

 {       
try
 {           

if (sm.getSearch() != null)

     {
       search(sm.getSearch());
     }
  }          

catch (Exception ex)
{
Label1.Text = ex.ToString();
} 

}

---

You should not create a new instance of SiteMaster() So remove the line SiteMaster sm = new SiteMaster(); from your ProductSearch class

Try this in your Page_Load

SiteMaster sm = Page.Master as SiteMaster;

if(sm!=null)
{
   if (sm.getSearch() != null)
   {
       search(sm.getSearch());
   }   
}

---

SiteMaster MasterPage = (SiteMaster)Page.Master;

That's how you will have to access the masterpage given that you have properly set up the masterpage.