CSS and HTML compatibility with all browsers

I have a website: [login to view URL] It works fine with Firefox and Internet Explorer. But with IE, as you can see, drop down CSS menu is distorted. I tried to insert "doctypes", but then it distorts left menu and bottom. *I need you to make this one particular page([login to view URL]), to be seen in all browsers, not only in Firefox. I will give you all source code. *I need you to put links in drop down menus, which I will give you later. *Drop down buttons needs to be aligned at the center of this page. (As you can see, currently it is on the left.)