case FuncName.SUBSTRING_BEFORE: case FuncName.SUBSTRING_AFTER: 	throw new UnsupportedException("Some functions are not supported");
case FuncName.SUBSTRING_BEFORE:	return subStringBefore(vn); case FuncName.SUBSTRING_AFTER: 	return subStringAfter(vn);
	public String evalString(VTDNav vn) throws UnsupportedException{	    int d=0;	  switch(opCode){	  		case FuncName.CONCAT:	  		    return concat(vn);	  		    //throw new UnsupportedException("Some functions are not supported");	  		    			case FuncName.LOCAL_NAME:			    return getLocalName(vn);			case FuncName.NAMESPACE_URI: 			    return getNameSpaceURI(vn);			case FuncName.NAME: 					    return getName(vn);			case FuncName.STRING:			    return getString(vn);			case FuncName.SUBSTRING_BEFORE:					case FuncName.SUBSTRING_AFTER: 	throw new UnsupportedException("Some functions are not supported");				case FuncName.SUBSTRING: 	return subString(vn);				case FuncName.TRANSLATE: 	throw new UnsupportedException("Some functions are not supported");			case FuncName.NORMALIZE_SPACE:throw new UnsupportedException("Some functions are not supported");			default: if (isBoolean()){			    		if (evalBoolean(vn)== true)			    		    return "true";			    		else 			    		    return "false";					 } else {					     return ""+ evalNumber(vn);					     					 }	  }	}	