pass a variable in mvc

Hi,

  i face problem in passing a variable on attachpress event

ex:

var a=10;

var editButton = new sap.m.Button({

    text : "Edit",

  icon : "sap-icon://edit",

  press : oController.editButton(a),

  });

it is not passing the variable.can anyone help me in fixing this.it shows"cannot read property 0 of undefined"