function getcss(cssfile){

loadcss = document.createElement('link')

loadcss.setAttribute("rel", "stylesheet")

loadcss.setAttribute("type", "text/css")

loadcss.setAttribute("href", cssfile)

document.getElementsByTagName("head")[0].appendChild(loadcss)

}

if(screen.width <= '800') 
// Defines the resolution range you're targeting (less than 800 pixels wide in this case)

{

getcss('800x600.css') 
// Defines the .css file you want to load for this range (800x600.css)

}



else if(screen.height > '500' && screen.height < '800') 
// This time we're targeting all resolutions between 800 and 1280 pixels wide

{

getcss('style_sm.css') 
//And we want to load the .css file named "1024x768.css"

}


else if(screen.height > '800' && screen.height < '1200')
//Targeting screen resolutions between 1024 and 1600px wide

{

getcss('style.css')
//Load 1280x1024.css

}



else 

{

getcss('1280x1024.css')
//This else statement has "if" condition. If none of the following criteria are met, load 1280x1024.css

}