function substringBefore(s, c) {
	if (s != null) {
		var res = '';
		var pos = s.indexOf(c);
		if (pos > -1) {
			res = s.substring(0, pos);	
		}
		return res;
	} else {
		return null;	
	} 		
}

function substringBeforeLast(s, c) {
	if (s != null) {
		var res = '';
		var pos = s.lastIndexOf(c);
		if (pos > -1) {
			res = s.substring(0, pos);	
		}
		return res;
	} else {
		return null;	
	} 		
}

function substringAfter(s, c) {
	if (s != null) {
		var res = '';
		var pos = s.indexOf(c);
		if (pos > -1) {
			res = s.substring(pos+c.length);	
		}
		return res;
	} else {
		return null;	
	} 		
}

function substringAfterLast(s, c) {
	if (s != null) {
		var res = '';
		var pos = s.lastIndexOf(c);
		if (pos > -1) {
			res = s.substring(pos+c.length);	
		}
		return res;
	} else {
		return null;	
	} 		
}

function startsWith(s, c) {
	if (s != null && c != null) {
		if (c.length <= s.length && c.length > 0) {
			if (c == s.substring(0, c.length)) {
				return true;
			}	
		}
	}
	return false;	
}

function abbreviate(s, len) {
	if (s != null) {
		if (s.length > len) {
			s = s.substr(0, len-3) + '...';
		}
		return s;
	}
	return null;	
}

function leftTrim(stringa) {
	while (stringa.substring(0,1) == ' ') {
		stringa = stringa.substring(1, stringa.length);
	}
	return stringa;
}

function rightTrim(stringa) {
	while (stringa.substring(stringa.length-1, stringa.length) == ' ') {
		stringa = stringa.substring(0,stringa.length-1);
	}
	return stringa;
}


function trim(stringa) {
	while (stringa.substring(0,1) == ' ') {
		stringa = stringa.substring(1, stringa.length);
	}
	while (stringa.substring(stringa.length-1, stringa.length) == ' ') {
		stringa = stringa.substring(0,stringa.length-1);
	}
	return stringa;
}	

function isEmpty(s) {
	if (s != null) {
		if (trim(s).length > 0) {
			return false;	
		}
	}
	return true;
}

function leftPad(s, c, len) {
	if (s == null)
		s = '';
	while (s.length < len) {
		s = c + s;
	}	
	return s;
}

function rightPad(s, c, len) {
	if (s == null)
		s = '';
	while (s.length < len) {
		s += c;	
	}	
	return s;
}