Search From start date to end date with textboxes

Hi all, im trying to search data in my MySQL database by date range from 2 textboxes (ie "tbStartDate", "tbEndDate"), but the user must only be allowed to search up to a maximum of only 31 days anything over that a error must be thrown, I have a query that retrieves all the information shown below but now need that date range search from a button click to show only certain record please help

("SELECT transactions.transaction_id, transactions.date_time, transaction_type.transaction_type_description, transactions.amount FROM `transactions`" +
        "INNER JOIN transaction_type ON transaction_type.transaction_type_id = transactions.transaction_type_id INNER JOIN member_detail ON member_detail.member_id = transactions.account_or_member_id " +
        "WHERE account_or_member_id = @member_id and is_member = '1' and transactions.transaction_type_id = '5' " +
        "Order by transactions.date_time ASC",con2)

any help would be appreciated, been battling with this function.
Wes

Tags: C# (C# 4.0), ASP.NET