Making or creating comma separated value list in a single line using SQL SP or UDF

Most of the times we need to display a summary or quotation line in our page by making a comma separated value list from SQL Server table data rows. But the reality is we did not get any built in function from SQL Server. But we did it by applying few techniques. Lets for SQL Server we can use the COALESCE function, In SQL Server 2000 we can use a variable smartly in our SELECT statement. To do