Bug 146548 [regression]Data type convert in chart data binding doesn't work.
Description: Data type convert in chart data binding doesn't work. Steps to reproduce: 1. New sample data source and dataset from OFFICES. 2. Insert a chart, bind it to dataset 3. Edit data binding to change officecode from string type to integer type 4. Drag officecode to y-series Expected result: No errors. Actual result: Unable to use a text data to render a numerical/datetime axis. org.eclipse.birt.chart.exception.ChartException at: org.eclipse.birt.chart.factory.Generator.build(Generator.java:985) org.eclipse.birt.chart.ui.swt.wizard.internal.ChartPreviewPainter.updateBuffer(ChartPreviewPainter.java:152) org.eclipse.birt.chart.ui.swt.wizard.internal.ChartPreviewPainter.renderModel(ChartPreviewPainter.java:333) org.eclipse.birt.chart.ui.swt.wizard.TaskSelectData.doLivePreview(TaskSelectData.java:1043) org.eclipse.birt.chart.ui.swt.wizard.TaskSelectData.changeTask(TaskSelectData.java:984) org.eclipse.birt.chart.ui.swt.wizard.ChartAdapter.notifyChanged(ChartAdapter.java:68) org.eclipse.emf.common.notify.impl.BasicNotifierImpl.eNotify
data/org.eclipse.birt.data/src/org/eclipse/birt/data/engine/expression/ExprEvaluateUtil.java
int oper = ( (IConditionalExpression) dataExpr ).getOperator( );
				IScriptExpression operand1 = ( (IConditionalExpression) dataExpr ).getOperand1( );
				IScriptExpression operand2 = ( (IConditionalExpression) dataExpr ).getOperand2( );
				
				return ScriptEvalUtil.evalConditionalExpr( doEvaluateRawExpression( opr,
						scope,
						javaType ),
						oper,
						doEvaluateRawExpression( operand1, scope, javaType ),
						doEvaluateRawExpression( operand2, scope, javaType ) );
			}
			else
			{
				assert false;
				return null;
			}
			
		}
		finally
		{
			Context.exit( );
		}
	}
	
	
		
	/**
	 * TODO: need refactoring
	 * 
	 * @param dataExpr