Unable to right click on the Digital signature certificate field thus unable to apply DSC

I am also facing the same issue. The right click is not working on the digital signature field. How I can apply my DSC(Digital signature certificate USB token) when right click options are not available.? Need urgent help on this. For form is http://www.mca.gov.in/MCA21/dca/downloadeforms/eformTemplates/NCA/Form_DIR-3.zip  try to right click on the Digital signature fields, nothing happens. I need solution for this.