var renderTemplate = function (tpl, dict) { if (!dict) return tpl; for (var key in dict) { tpl = tpl.replace( new RegExp("{"+key+"}", "g"), dict[key] ); } return tpl; }; // usage example: document.getElementsByTagName('body')[0].innerHTML = renderTemplate("<p class={class}>{content}</p>", { class: "foo", content: "lorem ipsum dolor" });