Bug 201019 [Automation][Regression]Exception is thrown when running reportdesign
engine/org.eclipse.birt.report.engine/src/org/eclipse/birt/report/engine/adapter/ExpressionUtil.java
* @return
	 */
	private static int advanceToNextValidEncloser( char[] chars, int i )
	{
		boolean isTotalConstants = true;
		int numberOfOpenBracket = 0;
		while ( i < chars.length )
		{
			ParseIndicator pid = getParseIndicator( chars, i, false, true,true);
			i = pid.getNewIndex( );
			if( pid.isCandidateKey( ))
			if ( chars[i] == '(' )
			{
				isTotalConstants = false;
				numberOfOpenBracket ++;
			}
			if ( isTotalConstants )
			{
				if ( !isValidProceeding( chars[i] ) )
					i++;
				else
					break;
			}
			else
			{
				if ( chars[i] != ')' )
					i++;
				else
				{
					if( chars[i] == ')')