Including js behavior inside a textfield

can someone help me with textfield? how do i get this to work?

<%= text_field :item, :barcode, :size => 21, :onclick=>
“clickclear(this, ‘insert barcode here’)” %>

the above line as it stands does not like the variable ‘this’ inside the
clickclear (js) function…

i’ve also tried playing around with html options but not sure of the
direction to go here…

: T