Bug 191685 [regression]Set default value doesn't work in Report Parameter[0705]
UI/org.eclipse.birt.report.designer.ui/src/org/eclipse/birt/report/designer/ui/dialogs/ParameterDialog.java
if ( canBeBlank( ) )
		{
			if ( StringUtil.isBlank( value ) )
			{
				return null;
			}
		}
		else
		{
			if ( StringUtil.isBlank( value ) )
			{
				return ERROR_MSG_CANNOT_BE_BLANK;
			}
		}
		try
		{
			getValue( value );
		}
		catch ( BirtException e )
		{
			return ERROR_MSG_MISMATCH_DATA_TYPE;
		}
		return null;
	}
	private boolean isEqual( String value1, String value2 )
	{
		Object v1 = null;
		Object v2 = null;
		try
		{