Password case sensitive

Question

I am developing a windows application, my database is in MS-Access. I have made one login form and the users who are authorised can login to the application. My problem is that if the user has made his password using lower case then at the login time the user should enter the password in the same format, means if the user enters the password in upper case then the error will be pop up. I mean to say that whatever case the user used while making the password then he/she should enter in the same format at the login time. That means that the password field should be made case sensitive. Please help me out as this is very urgent and important for me.