error in Sentence detector program

[dhanashree thakur]

hi all, I am running sentence detector program in eclipse ,but it gives
errors as,
Exception in thread "main" java.lang.NullPointerException
    at
opennlp.tools.util.model.BaseModel.getManifestProperty(BaseModel.java:491)
    at
opennlp.tools.util.model.BaseModel.initializeFactory(BaseModel.java:245)
    at opennlp.tools.util.model.BaseModel.loadModel(BaseModel.java:237)
    at opennlp.tools.util.model.BaseModel.<init>(BaseModel.java:181)
    at opennlp.tools.sentdetect.SentenceModel.<init>(SentenceModel.java:95)
    at SentenceSplit1.main(SentenceSplit1.java:21)

Please help me regarding this.