function sprintf() {
	if (!arguments || arguments.length < 1 || !RegExp) {
		return false;
	}

	var str = arguments[0];
	var re = /([^%]*)%('.|0|\x20)?(-)?(\d+)?(\.\d+)?(%|b|c|d|u|f|o|s|x|X)(.*)/;
	var a = b = [], numSubstitutions = 0, numMatches = 0;
	while (a = re.exec(str)) {
		var leftpart = a[1], pPad = a[2], pJustify = a[3], pMinLength = a[4];
		var pPrecision = a[5], pType = a[6], rightPart = a[7];
		//alert(a + '\n' + [a[0], leftpart, pPad, pJustify, pMinLength, pPrecision);
		
		numMatches++;
		if (pType == '%') {
			subst = '%';
		}
		else {
			numSubstitutions++;
			if (numSubstitutions >= arguments.length) {
				alert('Error! Not enough function arguments (' + (arguments.length - 1) + ', excluding the string)\nfor the number of substitution parameters in string (' + numSubstitutions + ' so far).');
			}

			var param = arguments[numSubstitutions];
			var pad = '';
			
			if (pPad && pPad.substr(0,1) == "'") pad = leftpart.substr(1,1);
			else if (pPad) pad = pPad;

			var justifyRight = true;

			if (pJustify && pJustify === "-") justifyRight = false;

			var minLength = -1;

			if (pMinLength) minLength = parseInt(pMinLength);

			var precision = -1;

			if (pPrecision && pType == 'f') precision = parseInt(pPrecision.substring(1));

			var subst = param;

			if (pType == 'b') subst = parseInt(param).toString(2);
			else if (pType == 'c') subst = String.fromCharCode(parseInt(param));
			else if (pType == 'd') subst = parseInt(param) ? parseInt(param) : 0;
			else if (pType == 'u') subst = Math.abs(param);
			else if (pType == 'f') {
				subst = (precision > -1) ? Math.round(parseFloat(param) * Math.pow(10, precision)) / Math.pow(10, precision): parseFloat(param);
				if(precision > 0) {
					subst=String(subst);
					var nbZero = precision;
					nbZero -= subst.indexOf('.')!=-1?subst.substr(subst.indexOf('.')+1).length:0;
					subst+=(subst.indexOf('.')!=-1?'':'.')+new Array(nbZero+1).join('0');
				}
			}
			else if (pType == 'o') subst = parseInt(param).toString(8);
			else if (pType == 's') subst = param;
			else if (pType == 'x') subst = ('' + parseInt(param).toString(16)).toLowerCase();
			else if (pType == 'X') subst = ('' + parseInt(param).toString(16)).toUpperCase();
		}
		str = leftpart + subst + rightPart;
	}
	return str;
}