Typing problem. I have Dell Inspiron 1526. It works fine but when I start typing the cursor will

Question

I have Dell Inspiron 1526. It works fine but when I start typing the cursor will move to the middle of the row and start typing there or it goes to the left of the row. Another problem is that when I type typing stops suddenly and i need to stare at the monitor all the time. Please help! Thank you.