Bug 201030 NPE throws out when preview the attached report design
data/org.eclipse.birt.data/src/org/eclipse/birt/data/engine/script/ScriptEvalUtil.java
public static Object evalConditionalExpr( Object obj, int operator,
			Object Op1, Object Op2 ) throws DataException
	{
		return evalConditionalExpr( obj, operator, new Object[]{
				Op1, Op2
		} );
	}
	
	/**
	 * 
	 * @param obj
	 * @param operator
	 * @param op1
	 * @param op2
	 * @return A Boolean result
	 * @throws DataException
	 */
	public static Object evalConditionalExpr( Object obj,
			int operator, Object[] ops )
			throws DataException
	{
		ExprTextAndValue[] opTextAndValue = new ExprTextAndValue[ops.length]; 
		for( int i=0; i< ops.length; i++ )
		{
			opTextAndValue[i] = createExprTextAndValueInstance( ops[i] );
		}
		
		Object resultObject = obj;
		Object[] resultOp = new Object[ops.length];
		for( int i=0; i< ops.length; i++ )