Calling javascript function from CS page

Calling javascript function from CS page

var message = "<script type=text/javascript>SaveDraft();</script>";
             System.Web.UI.ClientScriptManager clientScriptManager = Page.ClientScript;
             clientScriptManager.RegisterStartupScript(this.GetType(), "Add", message);

or

var message = "<script type=text/javascript>alert('TemplateName already exists, please change the name');</script>";
                        System.Web.UI.ClientScriptManager clientScriptManager = Page.ClientScript;
                        clientScriptManager.RegisterStartupScript(this.GetType(), "Message", message);


ASPX page
function SaveDraft() {
        alert('Support details saved successfully!');
        }