Rollover images

Hey guys, I´m having trouble with my code, I have this image and i want it to change when the mouse passes over. I tried this code but it´s not working 🙁

<img src=”URL OF FIRST IMAGE GOES HERE” onmouseover=”this.src=’URL OF SECOND IMAGE GOES HERE'”
onmouseout=”this.src=’URL OF FIRST IMAGE GOES HERE'” />

Thx!!