put all three in the div and ID them...
Code:
<img id="PC" ... />
<img id="Tablet" ... />
<img id="Mobile" ... />
then in your CSS (since you said you handle the platforms- and I presume the calls to the CSS files pend the platform) target accordingly... so for example the "PC" one might have this chunk of code
Code:
#PC {style it}
#Tablet {display:none;}
#Mobile {display:none;}
I have not yet coded for mobile devices and tablets, but I thought you did a lot more in the handling of determining "what the device is" server side script- if so you could also handle this server side script as well I assume but again my XP mobile/tab dev is null