I assume that the problem is only related to using Internet Explorer, since IE and FF handle file input in a slightly different way: in FF you can click on a button or field to open the Open dialog box, while in IE you can click on or double-click on the field.
WebDriver , , .
Selenium 1, JavaScript . WebDriver, JavaScript:
WebElement upload = driver.findElement(By.name("Passport"));
((JavascriptExecutor)driver).executeScript("arguments[0].click();", upload);
abouve Firefox, - :
WebElement upload = driver.findElement(By.name("Passport"));
if (driver instanceof InternetExplorerDriver) {
((JavascriptExecutor)driver).executeScript("arguments[0].click();", upload);
} else {
upload.click();
}