How to highlight the address bar automatically while opening a new tab in mozilla?

Previously, I could start typing in url bar as soon as a new tab is opened. The url bar used to be highlighted and I could simply type my search without selecting it anymore. But now, The url in the new tab is not highlighted anymore and the cursor is placed on the far right of the url bar. So, now when i type something in the bar my typed text get added to the url address and i can't search accordingly. So guys, please help me to solve this problem. I would like to do it without any extensions or add-ons. I would be thankful to all of you for your efforts. Thanks.