Modal PopUp in SharePoint

Have always got stuck in this.


/// <summary>
        /// Generates a modal popup
        /// </summary>
        /// <param name="sTitleOfThePage"></param>
        /// <param name="sWidthOfTheWindow"></param>
        /// <param name="sHeightOfTheWindow"></param>
        /// <param name="LinkOfThePageThatNeedsToBeOpened"></param>
        private void CallModalPopUp(string sTitle, string sWidth, string sHeight, string newLink)
        {
            string command = "ExecuteOrDelayUntilScriptLoaded(function () {var options = SP.UI.$create_DialogOptions(); options.title = \""+sTitle+"\"; options.width = "+sWidth+"; options.height = "+sHeight+"; options.url = \"" + newLink + "\"; SP.UI.ModalDialog.showModalDialog(options);}, \"sp.js\");";

            Page.ClientScript.RegisterStartupScript(this.GetType(), "PopupScript", command, true);
        }