tsql LastIndexOf

ALTER FUNCTION [dbo].[LastIndexOf] (@stringValue as nvarchar(1000), @stringSearch as nvarchar(1000))
 returns int
AS
BEGIN
     DECLARE @lastindex int
     SET @lastindex= 0
     DECLARE @tempindex int
     while (1=1)
     begin
        SET @tempindex = charindex(@stringSearch, @stringValue, @lastindex + 1)
        if (@tempindex = 0)
            break
        SET @lastindex = @tempindex
     end
    
     RETURN(@lastindex) 
END