function trim (s) {
	if (s != null) {
		var trimmed = s.replace(/^\s+|\s+$/g, '') ;
		if (trimmed.length > 0) {
			return trimmed;
		}
	} 
		
	return null;
}


function getParameter (parameterName) {
	// Add "=" to the parameter name (i.e. parameterName=value)
	var parameterName = parameterName + "=";
	var queryString = null;
	
	if (window.top.location.search != 0) {
		queryString = window.top.location.search;
	}

	if (queryString.length > 0) {
		// Find the beginning of the string
		begin = queryString.indexOf (parameterName);

		// If the parameter name is not found, skip it, otherwise return the value
		if (begin != -1) {
			
			// Add the length (integer) to the beginning
			begin += parameterName.length;
			
			// Multiple parameters are separated by the "&" sign
			end = queryString.indexOf ("&" , begin);
			if (end == -1) {
				end = queryString.length
			}
			
			// Return the string
			return unescape (queryString.substring (begin, end));
		}
	}

	// Return null if no parameter has been found
	return null;
}