ScriptResourceMapping

vs2012 website project by attaching validator gives this error. Solution pls.
""[InvalidOperationException: WebForms UnobtrusiveValidationMode requires a ScriptResourceMapping for 'jquery'. Please add a ScriptResourceMapping named jquery(case-sensitive).]    System.Web.UI.ClientScriptManager.EnsureJqueryRegistered() +2170706    System.Web.UI.WebControls.BaseValidator.RegisterUnobtrusiveScript() +10    System.Web.UI.WebControls.BaseValidator.OnPreRender(EventArgs e) +9576593    System.Web.UI.Control.PreRenderRecursiveInternal() +83    System.Web.UI.Control.PreRenderRecursiveInternal() +168    System.Web.UI.Control.PreRenderRecursiveInternal() +168    System.Web.UI.Control.P ...