get spsuer using object model

this is for get spuser... code using object model

 /// <summary>
        /// Returns the SPUser Object built based on the OOTB people or groups field type of sharepoint.
        /// Get SPUser Object from a SharePoint list item people or group field value.
        /// Can be used to get the user object properties, e.g. email of the user.
        /// </summary>
        /// <param name="spListItem">Source list item</param>
        /// <param name="fieldName">column/field name, e.g., "PersResponsible"</param>
        /// <returns></returns>

        public SPUser GetSPUserObject(SPListItem spListItem, String fieldName)
        {
            SPUser spUser = null;
            try
            {
                if (fieldName != string.Empty)
                {
                    SPFieldUser field = spListItem.Fields[fieldName] as SPFieldUser;
                    if (field != null && spListItem[fieldName] != null)
                    {
                        SPFieldUserValue fieldValue = field.GetFieldValue(spListItem[fieldName].ToString()) as SPFieldUserValue;
                        if (fieldValue != null)
                        {
                            spUser = fieldValue.User;

                        }
                    }
                }
            }
            catch (Exception ex)
            {
              
            }

            return spUser;
        }