Friendly error message for FK

IF NOT EXISTS (SELECT TOP 1 1 FROM ObjectMainMessages WHERE ObjectName = 'FK_item_ILC_InfoCard' AND MessageType = 18)
    BEGIN
        DECLARE @NextMessageNo  int
        DECLARE @NextMessageNoNext  int

        SELECT @NextMessageNo   = ISNULL(MAX(messageno),799999)
        FROM ApplicationMessages
        WHERE MessageNo BETWEEN 800000 AND 999999

        SET @NextMessageNo = @NextMessageNo + 1
        SET @NextMessageNoNext = @NextMessageNo + 1

        ---add main message 404 = Cannot delete record. At least one &1 exists for this &2.
        EXEC AddObjectMainMessageSp 'FK_item_ILC_InfoCard', 18, 404, 16, 'Item to InfoCard FK violation', 0

        --add the substitution text
        EXEC AddApplicationMessageSp @NextMessageNo, 'Item', N'1033'
        EXEC AddApplicationMessageSp @NextMessageNoNext, 'InfoCard', N'1033'

        --add substitution text to main message
        EXEC AddObjectBuildMessageSp 'FK_item_ILC_InfoCard', 18, 1, @NextMessageNo
        EXEC AddObjectBuildMessageSp 'FK_item_ILC_InfoCard', 18, 2, @NextMessageNoNext
    END