Bug 124610 Add a filter on a boolean computed column will cause error.
Description: Add a filter on a boolean computed column will cause error. Steps to reproduce: 1. New a BIRT sample data source and a dataset from table "orders" 2. Create a computed column with name="yes/no", type = any(no boolean for choose), value= if(row[1]%2==0){ true; }else{ false; } 3. Drag the dataset from Data Explorer to Layout 4. Select the table, click Filters tab in Property Editor. 5. Click Add button. 6. Select yes/no as Expression, Is True as Operator. 7. Save and preview. Expected result: Filter works. Actual result: Error0 : data.engine.ConvertToDataTypeError ( 1 time(s) ) detail : org.eclipse.birt.data.engine.core.DataException: can not be converted to class java.lang.Boolean.
data/org.eclipse.birt.data/src/org/eclipse/birt/data/engine/script/ScriptEvalUtil.java
}
	}
	
	/**
	 * Evaluates a IJSExpression or IConditionalExpression
	 * 	
	 * @param expr
	 * @param cx
	 * @param scope
	 * @param source
	 * @param lineNo
	 * @return 
	 * @throws DataException
	 */
	public static Object evalExpr( IBaseExpression expr, Context cx, Scriptable scope, 
				String source, int lineNo )
		throws DataException
	{
		if ( logger.isLoggable( Level.FINER ) )
			logger.entering( ScriptEvalUtil.class.getName( ),
				"evalExpr",
				"evalExpr() expr="
						+ LogUtil.toString( expr ) + ", source=" + source
						+ ", lineNo=" + lineNo );
		Object result;
		if ( expr == null )
		{
			result = null;
		}
		else if ( expr instanceof IConditionalExpression)