Not able to click on "Search" button Java Selenium Web driver

Question

I am trying to click on "Search" button but no luck. I also tried searching for iframe but there is no iframe. Here is my "Search" button html tag:

<input type="submit" value="search">

Here is xpath that I am using in order to click on Search button:

driver.findElement(By.xpath("//*[@id='mainDiv']/table/tbody/tr/td/div[3]/blockquote/fieldset/input[1]")).click();

Following methods I have tried:

1. new Actions(driver).moveToElement("//*[@id='mainDiv']/table/tbody/tr/td/div[3]/blockquote/fieldset/input[1]").perform();

2. JavascriptExecutor jse = (JavsscriptExecutor)driver; jse.executeScript("document.getElementById(//*[@id='mainDiv']/table/tbody/tr/td/div[3]/blockquote/fieldset/input[1]").focus().click();");

3. new WebDriverEait(driver, 10).until(ExpectedConditions.ElementToBeClickable(By.cssSelector(Inpout.submit[value='search']"))).click();

4. driver.findElement(By.cssSelector(".submit[value='search']")).click();