I want to insert text with single quote Eg john's to table in sql server 2005 database
Escape single quote with an additional single as Kirtan pointed out
And if you are trying to execute a dynamic sql (which is not a good idea in the first place) via sp_executesql then the below code would work for you
sp_executesql N'INSERT INTO SomeTable (SomeColumn) VALUES (''John''''s'')'