javascript replace with regexp

Question

I have a string that contains a lot of

<span style="font-size:8px;">...</span> 
<span style="font-size:14px;"> ...</span>

And i want to replace all font-size values to given value. So i need a regexp to replace all chars beetween "font-size:" and "px;"

Ps i use Rangy JS library

var iframe = $('iframe')[0];
            var sel =  rangy.getIframeSelection(iframe);
            selected_html=sel.toHtml();
            selected_html.replace("font-size:<some regexp>px;", "36");

Can you suggest a proper regexp?

Answer 1

.replace(/(font-size:)\d+(px;)/g, "$1"+36+"$2");