function Agreement(btnID,chkID,lblID)
{
  if(lblID != null)
  {
    this._lblID = document.getElementById(lblID);
  }
  this._btnContinue = document.getElementById(btnID);
  this._cbCheckBox = document.getElementById(chkID);
  this.SetCheckBox = function(bln) 
  {
    this._cbCheckBox.checked = bln;
  }
}

Agreement.prototype.IsValid = function()
{
   return this._cbCheckBox.checked;
}

Agreement.prototype.EnableButton = function(bln)
{
    this._btnContinue.disabled = !bln;
}