Pass parameter: From one User control to another User control

From usercontrol1 pass values into usercontrol2 is easy . make public property like

public TextBox txtFromUserControl2
{ get {return txtbox;}

set {txtbox = value;}

}

and then from user control1, just call UserControl2.txt box FormUserControl2 and it will allow you set or get this object

From UserControl2 call userControl1 is little trick, you can use delegate or bubble event