$('#copy_button').click(function(){
  copyFormValues( $('#form1'), $('#form2') );
});

function copyFormValues ( $source_form, $target_form ) {
  
  $source_form.find(':input').each(function(){
    
    var field_name = $(this).attr('name'),
        field_value = $(this).val();
    
    $target_form.find('[name='+field_name+']').val(field_value);
  });
  
}