SharePoint 2007: How to verify if a user is a Site Administrator

In many Sharepoint projects the following code has been user to check if a certain user has full control or not over a specific site:
if (!SPContext.Current.Web.CurrentUser.IsSiteAdmin)

But this code only check if a user is a Site Collection administrator. Even if the current user is in the owners group, it will not work. And therefore, problems will happen once implemented live.

Workaround:
I wrote a method that checks if a user belongs to the Owners group:
f(!isCurrentUserOwner())

Method:
private bool isCurrentUserOwner()
        {
            bool currentUserOwner = false;
            SPUser currentUser = SPContext.Current.Web.CurrentUser;
            SPSecurity.RunWithElevatedPrivileges(delegate()
            {
                try
                {
                    SPSite currentSite = new SPSite(SPContext.Current.Site.Url);
                    SPWeb currentWeb = currentSite.OpenWeb(SPContext.Current.Web.ID);
                    SPGroup ownersGroup = currentWeb.AssociatedOwnerGroup;
                    //Check if currentuser belongs to owners group of the current web
                    foreach(SPUser user in ownersGroup.Users)
                    {
                        if (currentUser.ID == user.ID)
                        {
                            currentUserOwner = true;
                        }
                    }
                }
                catch (Exception ex)
                {
                    //blah blah
                }             
            });
            //Not an owner member
            return currentUserOwner;
        }