How to change the font size on mobile devices using javascript

[AndiJ]

I tried the following syntax but it didn't work on mobile though it is working on the desktop version.\[code\]if(navigator.userAgent.match(/iPhone/i)) { document.getElementsByTagName("body")[0].style.fontSize="40%"; //and $("body").css("font-size","40%");}\[/code\]I even tried using \[code\]createElement\[/code\] but failed to get success:\[code\]if(navigator.userAgent.match(/iPhone/i)) { alert("iphone"); var create=document.createElement("link"); var body=document.getElementsByTagName("body")[0]s; alert(body); create.href="http://stackoverflow.com/questions/13855860/css/Iphone_1414.css"; create.rel="stylesheet"; create.type="text/css"; body.appendChild(create);}\[/code\]Can anyone help me on the same.