Please Help How avoid Special Character in the column of a table in the SQL Server 2005 andhow html content insert in the textbox like text

Question

Please help
 1.How avoid Special Character in the column of a table in the SQL Server 2005
exp.
i made a table in the SQL Server for Asp.Net Application
in a table 4 column one is title.
i want in the title column user can not write special character.
and one more problem
2. how html content add in the column like text  insert user in the text box if user insert html content what condition require