You can add action buttons to navigate through the slides. To do so, click
AutoShapes under the drawing toolbar, select Action Buttons. You will get
several buttons such as next, previous, beginning, end, and etc. Select the
button you want, and add it onto the slide. Click ok when the action settings
window appears.

If you want to type text during presentation, you can add a textbox from the
control toolbox. To enable the control toolbox, click View > Toolbar >
Control Toolbox. Look for the textbox button, click and add it onto the slide.

"the pps will as to type something"

Hey I'm just guessing here ...

Do you mean you'd like people to type in an answer or password and then
continue with the show. If that's it, you really will need to learn some
basic vba and use the msgbox or inputbox statements - these are only
available through vba.

You might want to check out this FAQ page, which is all about entering text
during a show. It gives you several options depending on what you really
want to do.

Adding or entering text during a show
http://www.pptfaq.com/FAQ00701.htm

--David