Js function call on cs side

 ClientScript.RegisterStartupScript (GetType(), "Javascript", "javascript: fnShowMessage(); ", true);

ScriptManager.RegisterStartupScript(Page, Page.GetType(), Guid.NewGuid().ToString(), "nextResource();", true);

this.Page.ClientScript.RegisterClientScriptBlock(this.GetType(), "aa", "$('#overlay').show(); $('.form_close').addClass('active');$('.rent_now_wrapper').animate({ left: 0 }, 500);", true);

this.Page.ClientScript.RegisterClientScriptBlock(this.GetType(), "aa", "alert(1);", true);