SPServices Check Is user is in a Perticual group.

var groupname="your group name";

function IsUserInGroup(){
jQuery().SPServices({
      operation: "GetGroupCollectionFromUser",
      userLoginName: jQuery().SPServices.SPGetCurrentUser(),
      async: false,
      completefunc: function(xData, Status) {      
        jQuery(xData.responseXML).find("Group").each(function(){
if(jQuery(this).attr("Name") == groupname)
{
//Method to call if user is in perticualr group.
executeifOwners();
return;
}
});
}
    });
}