merge form data on js {js, form, serialize, merge}

mergeFormData.js

/**
 * Get data from many forms
 * Work in IE11+ and work with file ajax upload
 */
var
	data = new FormData($('#form1')[0]),
	form_2 	= $('#form2').serializeArray();

form_2.forEach(function(fields){
	data.append(fields.name, fields.value);
});