Removing non-alpha characters & spaces script...

Hi I am trying to strip out any non-alpha characters from a field.

i.e. Field = ABC"_IT8*$ should return: ABCIT8

I am writing a loop to do this for all values of a field. The script runs, but hangs...please could somebody advise on the code below...:

I run the script but it doesn't seem to finish. Can anybody see any issues with the code:

DECLARE @.Index SMALLINT,
@.MATCH_Supplier_name varchar(500),
@.Counter numeric,
@.Max numeric
-- @.sqlstring varchar(500)

SET @.Counter = 1
SET @.Max = (SELECT Max(DTect_Supplier_SRN) FROM SUPPLIER_TABLE_TEST)

WHILE @.Counter <@.Max
BEGIN
SET @.MATCH_Supplier_name = (SELECT Match_Supplier_Name FROM SUPPLIER_TABLE_TEST WHERE @.Counter = DTect_Supplier_SRN)
SET @.Index = LEN(@.MATCH_Supplier_name)
WHILE @.Index > = 1
SET @.MATCH_Supplier_name = CASE
WHEN SUBSTRING(@.MATCH_Supplier_name, @.Index, 1) LIKE '[a-zA-Z]' TH EN SUBSTRING(@.MATCH_Supplier_name, @.Index, 1)
WHEN SUBSTRING(@.MATCH_Supplier_name, @.Index, 1) LIKE '[0-9]' THEN SUBSTRING(@.MATCH_Supplier_name, @.Index, 1)
ELSE ''
END + @.MATCH_Supplier_name
SET @.Index = @.Index - 1
--PRINT @.MATCH_Supplier_name
SET @.Counter = @.Counter + 1
ENDSET @.Max = (SELECT Max(DTect_Supplier_SRN) FROM SUPPLIER_TABLE_TEST)

Change it to count ...don't have much time now,check for other errors.|||Cheers, its all sorted now.