Fetch lookup value and set it another lookup field on differnt form

Hello there,

I have simple requirement, on button click event i want to fetch lookup field select value which is on lead form and set it to another lookup field which has on contact form

using javascript.and that contact form will be opened as new record.

1.Click of button(Lead form)

2.source value(lookup field selected)(Lead form)

3.set that value here(lookupfield))(Contact form)

both has different entities.

Thanks,

Regaards.