Bug 168318 [regression]Print doesn't work correctly when preview attached file through external browser[00]
engine/org.eclipse.birt.report.engine/src/org/eclipse/birt/report/engine/executor/ExecutionContext.java
return null;
	}	
	/**
	 * evaluate conditional expression. A conditional expression can have an
	 * operator, one LHS expression, and up to two expressions on RHS, i.e.,
	 * 
	 * testExpr operator operand1 operand2 or testExpr between 1 20
	 * 
	 * Now only support comparison between the same data type
	 * 
	 * @param expr
	 *            the conditional expression to be evaluated
	 * @return a boolean value (as an Object)
	 */
	public Object evaluateCondExpr( IConditionalExpression expr )
	{
		int operator = expr.getOperator( );
		IScriptExpression testExpr = expr.getExpression( );
		IScriptExpression v1 = expr.getOperand1( );
		IScriptExpression v2 = expr.getOperand2( );
		if ( testExpr == null )
			return Boolean.FALSE;
		Object testExprValue = evaluate( testExpr.getText( ) );
		if ( IConditionalExpression.OP_NONE == operator )
		{
			return testExprValue;
		}
		Object vv1 = null;
		Object vv2 = null;
		if ( v1 != null )