function getParameter ( queryString, parameterName ) {
	// Add "=" to the parameter name (i.e. parameterName=value)
	var parameterName = parameterName + "=";
	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";
		return null;
	}
}