Answers for "if a element is visible"

check if element is visible

.is(':visible')
//Selects all elements that are visible.

if($('#Div').is(':visible')){
	// add whatever code you want to run here.
}

$('#yourDiv:visible').callYourFunction();

to check element visible

if(driver.findElement(By.cssSelector("a > font")).isDisplayed())
{ System.out.println("Element is Visible"); 
}else{ System.out.println("Element is InVisible"); }