Bug 151381 [Smoke]The parameter didn't display in the web viewer
Description: Preview a parameter in the web viewer, it can't be previewed. Step to reproduce: 1. new a report and a parameter 2. drag it to the layout 3. preview it in the web viewer Actual result: the parameter is not displayed
core/org.eclipse.birt.core/src/org/eclipse/birt/core/data/DataTypeUtil.java
* @return
	 * @throws BirtException
	 */
	public static Object convert( Object source, int toType )
			throws BirtException
	{
		if ( source == null )
			return null;
		
		if ( toType == DataType.UNKNOWN_TYPE || toType == DataType.ANY_TYPE )
			return source;
		source = JavascriptEvalUtil.convertJavascriptValue( source );
		switch ( toType )
		{
			case DataType.INTEGER_TYPE :
				return toInteger( source );
			case DataType.DECIMAL_TYPE :
				return toBigDecimal( source );
			case DataType.BOOLEAN_TYPE :
				return toBoolean( source );
			case DataType.DATE_TYPE :
				return toDate( source );
			case DataType.DOUBLE_TYPE :
				return toDouble( source );
			case DataType.STRING_TYPE :
				return toString( source );
			case DataType.BLOB_TYPE :
				return toBlob( source );
			case DataType.BINARY_TYPE :
				return toBytes( source );