problem in updating data

Hi All, I've created an function for update record in database's table. the function can handle all the record update from any table... with parameter passed in .. like this : function update($table,$values,$condition) { $link=$this->database(); $fields = mysql_list_fields("wellindo", $table, $link); $columns = mysql_num_fields($fields); $field_values=""; for ($i = 1; $i < $columns-1; $i++) { $field_values=$field_values.mysql_field_name($fields, $i)."=".$values[$i].",";} $field_values=$field_values.mysql_field_name($fields, $i)."=".$values[$i]; $query = "UPDATE $table SET $field_values $condition"; $this->query($query,$table); } the function will find all the fields of the table then update all the data. the problem is that when there ar some fields that I dont want to update (I still want to use the existed/old data )... so how do I do that...?? eg : I hav record name phone country a 123 England and i want to update only phone change to 234.... what can do to set name and country so that it still remain the old data sorry for the awful explaination....hope someone can get it... thanx By regard; Sukanto