Google Search Gone in Safari

Hello,

Please anyone help, my google search that is normally in top right of screen has vanished. I have tried 'View-Customise Toolbar' and can see that the search bar is there to move but is greyed out. I can add other buttons and functions just not search... any ideas? (I have just put mountain lion though... could it be this?) i've attached a pic of what my brower looks like. (and the greyed out area of my customise tool) many thanks