In case you are using a team site :
if (Microsoft.SharePoint.SPContext.Current.FormContext.FormMode == SPControlMode.Edit)
{
ltr.Text = "EditMode2";
}
else
{
ltr.Text = "ViewMode";
}
in case you are using a publishing site:
if (Microsoft.SharePoint.SPContext.Current.FormContext.FormMode == SPControlMode.Display)
{
// your code to support display mode
}
else // Microsoft.SharePoint.SPContext.Current.FormContext.FormMode = SPControlMode.Edit
{
// your code to support edit mode
}




