New York--DoubleClick Inc., the leading online advertising network, said on Wednesday that it would cut its work force by 10% and make strategic changes to make its business more efficient. The company would not say how many jobs were being eliminated. The job cuts come on top of layoffs in December, when DoubleClick said it was axing less than 10% of its work force. Shares in the New York-based company were down at around $10 in early morning trading on the Nasdaq market, near a 52-week low of $8. The 52-week high was $114.