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/ColumnReferenceExpression.java
return m_columnIndex;
	}
	
	
	/**
	 * @see org.eclipse.birt.data.engine.expression.CompiledExpression#evaluate(org.mozilla.javascript.Context, org.mozilla.javascript.Scriptable)
	 */
	public Object evaluate(Context context, Scriptable scope) throws DataException
	{
		
		
		 
		
		StringBuffer expr = new StringBuffer( this.rowIndicator+"[");
		if ( isIndexed() )
		{
			expr.append(m_columnIndex);
		}
		else
		{
			expr.append('"');
			expr.append( JavascriptEvalUtil.transformToJsConstants( m_columnName ) );
			expr.append('"');
		}
		expr.append(']');
		return ScriptEvalUtil.evaluateJSAsExpr( context, scope, 
					expr.toString( ),"ROM Expression", 0);
	}
}