Bug 141255 No error for the incompatible parameter value
Steps to reproduce: 1.New a decimal parameter, set the default value to "aaa" 2.Preview the report by "Preview" tab Expected result: Error to say the incompatible parameter value Actual result: Parameter request page keeps poping up till input the decimal value Note: if preview in Web Viewer, error will be thrown out, but no exception description.
viewer/org.eclipse.birt.report.viewer/birt/WEB-INF/classes/org/eclipse/birt/report/context/ViewerAttributeBean.java
{
	/**
	 * Viewer preview max rows limited
	 */
	private int maxRows;
	/**
	 * Report parameter definitions list
	 */
	private Collection parameterList = null;
	/**
	 * Constructor.
	 * 
	 * @param request
	 */
	public ViewerAttributeBean( HttpServletRequest request )
	{
		try
		{
			init( request );
		}
		catch ( Exception e )
		{
			this.exception = e;
		}
	}