In selenium for inputbox, we can enter value like :
WebElement inputBox = driver.findElement(By.xpath(xpath)));
inputBox.sendKeys(\"abc\");
You can update the DIV text using JavaScript
JavascriptExecutor js = (JavascriptExecutor) driver;
js.executeScript("document.getElementById('Div_Id').innerHTML="+ DesiredText);
Using XPATH in JavaScript
JavascriptExecutor js = (JavascriptExecutor) driver;
js.executeScript("document.evaluate(xpathExpresion, document, null, 9, null).singleNodeValue.innerHTML="+ DesiredText);
Reference