Removing an image and a string

I need to remove an image I have drawn after 30 seconds. I’m currently using the code:

To load and draw the image

  
if(ofGetElapsedTimef() - lastEventTime <= 30.0f){  
		lowResLogo.loadImage("logo.png");  
		lowResLogo.draw(500, 500);  
}  
  

Then I have tried the clear method to remove, but this does not do it.

  
  
	if(ofGetElapsedTimef() - lastEventTime >= 30.0f){  
		lowResLogo.clear();  
	}  
  

Am I missing something simple here?

I have managed to get the above code working by changes the timings of the statements. My problem now is how do I remove a string. I want to delete the string below off the app after a certain amount of time. How can this be done?

  
  
blissTwo.drawString(ofToString(countdown, 0), 600, 400);  
// remove logo and coundown  
	if(ofGetElapsedTimef() - lastEventTime >= 29.9f){  
		lowResLogo.clear();  
	}  
	  

If I’m understanding you right, you just don’t draw the image if it’s been up too long:

  
  
  
ofClear(0, 0, 0, 1.f); // or whatever you want your background to be  
blissTwo.drawString(ofToString(countdown, 0), 600, 400);    
if(ofGetElapsedTimef() - lastEventTime <= 29.9f){    
    lowResLogo.draw();  
}