[FIX] board: use of event variable
[FIX] board: use of event variable

The global event variable is magically ok on some browsers
but not on firefox

(Thanks aab)

storm-computers/odoo,optima-ict/odoo,microcom/odoo,dfang/odoo,Elico-Corp/odoo_OCB,ygol/odoo,storm-computers/odoo,syci/OCB,optima-ict/odoo,dfang/odoo,mkieszek/odoo,mkieszek/odoo,hip-odoo/odoo,stephen144/odoo,stephen144/odoo,Elico-Corp/odoo_OCB,hip-odoo/odoo,laslabs/odoo,tvtsoft/odoo8,hip-odoo/odoo,ygol/odoo,optima-ict/odoo,ygol/odoo,optima-ict/odoo,laslabs/odoo,microcom/odoo,Elico-Corp/odoo_OCB,tvtsoft/odoo8,Elico-Corp/odoo_OCB,storm-computers/odoo,microcom/odoo,bplancher/odoo,tvtsoft/odoo8,mkieszek/odoo,dfang/odoo,syci/OCB,mkieszek/odoo,stephen144/odoo,tvtsoft/odoo8,Elico-Corp/odoo_OCB,bplancher/odoo,dfang/odoo,laslabs/odoo,sysadminmatmoz/OCB,laslabs/odoo,sysadminmatmoz/OCB,mkieszek/odoo,microcom/odoo,hip-odoo/odoo,tvtsoft/odoo8,hip-odoo/odoo,storm-computers/odoo,bplancher/odoo,stephen144/odoo,ygol/odoo,dfang/odoo,optima-ict/odoo,sysadminmatmoz/OCB,sysadminmatmoz/OCB,hip-odoo/odoo,sysadminmatmoz/OCB,ygol/odoo,ygol/odoo,microcom/odoo,microcom/odoo,stephen144/odoo,syci/OCB,laslabs/odoo,syci/OCB,bplancher/odoo,stephen144/odoo,storm-computers/odoo,bplancher/odoo,syci/OCB,sysadminmatmoz/OCB,bplancher/odoo,ygol/odoo,optima-ict/odoo,syci/OCB,laslabs/odoo,Elico-Corp/odoo_OCB,mkieszek/odoo,storm-computers/odoo,tvtsoft/odoo8,dfang/odoo,sysadminmatmoz/OCB