I'm using a javascript snippet in order for visitors to my site to increase the font size on all paragraphs using the following javascript:

function increaseFontSize() {  



    var paragraphs = document.getElementsByTagName('p'); 



    for(i=0;i<paragraphs.length;i++) {   



        if(paragraphs[i].style.fontSize) { 

            var s = parseInt(paragraphs[i].style.fontSize.replace(px,));

        } else {   

            var s = 14;

        }



        if(s != max) {  

            s += 1; 

        } 

        paragraphs[i].style.fontSize = s+px

    } 

} 

How can I also include li to this code so that p and li are the selected elements that are affected?

I would also like to avoid adding a class or an id to my li or ul. Is there a way to select two tags at once?