// http://kevin.vanzonneveld.net
// +   original by: Kevin van Zonneveld (http://kevin.vanzonneveld.net)

function substr_count( haystack, needle, offset, length ) {		 
	var pos = 0, cnt = 0;
 
	haystack += '';
	needle += '';
	if(isNaN(offset)) offset = 0;
	if(isNaN(length)) length = 0;
	offset--;
 
	while( (offset = haystack.indexOf(needle, offset+1)) != -1 ){
		if(length > 0 && (offset+needle.length) > length){
			return false;
		} else{
			cnt++;
		}
	}
 
	return cnt;
}
		
function trim (str, charlist) {
    var whitespace, l = 0, i = 0;
    str += '';
    
    if (!charlist) {
        // default list
        whitespace = " \n\r\t\f\x0b\xa0\u2000\u2001\u2002\u2003\u2004\u2005\u2006\u2007\u2008\u2009\u200a\u200b\u2028\u2029\u3000";
    } else {
        // preg_quote custom list
        charlist += '';
        whitespace = charlist.replace(/([\[\]\(\)\.\?\/\*\{\}\+\$\^\:])/g, '\$1');
    }
    
    l = str.length;
    for (i = 0; i < l; i++) {
        if (whitespace.indexOf(str.charAt(i)) === -1) {
            str = str.substring(i);
            break;
        }
    }
    
    l = str.length;
    for (i = l - 1; i >= 0; i--) {
        if (whitespace.indexOf(str.charAt(i)) === -1) {
            str = str.substring(0, i + 1);
            break;
        }
    }
    
    return whitespace.indexOf(str.charAt(0)) === -1 ? str : '';
}