Bug 192792 Drag to change xtab width will cause xls preview failure[1203]
engine/org.eclipse.birt.report.engine.emitter.prototype.excel/src/org/eclipse/birt/report/engine/emitter/excel/layout/LayoutUtil.java
DimensionType value = table.getColumn( i ).getWidth( );  
			if( value == null)
			{
				unmount.add( new Integer(i) );
			}
			else
			{
				index[i] = ExcelUtil.covertDimensionType( value, width ); 
				know += index[i];
			}	
		}		
		
		int left = width - know;
		
		if(left >= 0 && unmount.size( ) == 0)
		{
			return new DefaultTableInfo(index);
		}
		else if(left <= 0 && unmount.size( ) >= 0)
		{
			return new DefaultTableInfo(split(width, colcount));
		}
		else if(left > 0 && unmount.size( ) > 0)
		{
			int[] size = split(left, unmount.size());			
			Iterator iter = unmount.iterator( );
			int i = 0;
			
			while(iter.hasNext( ))
			{