Function To Strip HTML

I have the following function that I used in MSSQL. I would like to
create the same function in PostgreSql. I think I am a bit confused on
how to create and set variables in PostgreSql. Can someone give me a
place to start to create something like this?

Thanks

Pam

SET ANSI_NULLS ON

GO

SET QUOTED_IDENTIFIER ON

GO

CREATE FUNCTION [dbo].[udf_StripHTML]

(@HTMLText VARCHAR(MAX))

RETURNS VARCHAR(MAX)

AS

BEGIN

DECLARE @Start INT

DECLARE @End INT

DECLARE @Length INT

SET @Start = CHARINDEX('<',@HTMLText)

SET @End = CHARINDEX('>',@HTMLText,CHARINDEX('<',@HTMLText))

SET @Length = (@End - @Start) + 1

WHILE @Start > 0

AND @End > 0

AND @Length > 0

BEGIN

SET @HTMLText = STUFF(@HTMLText,@Start,@Length,'')

SET @Start = CHARINDEX('<',@HTMLText)

SET @End = CHARINDEX('>',@HTMLText,CHARINDEX('<',@HTMLText))

SET @Length = (@End - @Start) + 1

END

RETURN LTRIM(RTRIM(@HTMLText))

END

GO