Regexping for template

// Mimicing the MooTools supstitute method()

var reTag = /[{]{2}\s*([a-zA-Z0-9._\-]+)\s*[}]{2}/mig,
    reKey = /[a-zA-Z0-9._\-]+/ig,
    oResult = null,
    aKeys = Object.keys(jsonp),
    sTag = "",
    sKey = "";
while ((oResult = reTag.exec(template)) !== null) {
    sTag = oResult[0];
    sKey = oResult[0].match(reKey)[0];

    if (aKeys.contains(sKey)) {
        var sTagValue = jsonp[sKey.toString()],
            type = typeOf(sTagValue);

        template.replace(sTag, sTagValue);
        console.log(template, sTag, sTagValue);
    }

    //console.log(oResult[0], oResult.index, reTag.lastIndex, oResult[0].match(reKey)[0]);
}
console.log(template.substitute(jsonp));