i got married a girl after 4th day of marrig my wife said tht she had nikkah(court marriege) before but her ex husband has given her divorce on SMS and verbaly on phone for 1 time before 1 month of our nikah but she did not went to her ex husbnd house (no rukhsati) her ex husband also knows that she is getting married to someone but he did not bother and let the marriage go on
please tell me whether my nikkah is halal or what should i do now

All perfect praise be to Allaah, The Lord of the Worlds. I testify that there is none worthy of worship except Allaah, and that Muhammad is His slave and Messenger.

If the situation is as you mentioned in the question, that this woman had been divorced by her husband before the consummation of their marriage, then she did not have to observe a waiting period as Allaah Says about the women who were divorced before the consummation of the marriage (what means): {O you who have believed, when you marry believing women and then divorce them before you have touched them [i.e. consummated the marriage], then there is not for you any waiting period to count concerning them.}[Quran 33:49]

Based on this, your marriage to her is correct if this marriage took place fulfilling the conditions of a valid marriage, the most important of which is the consent of the guardian and the presence of two witnesses.

For more benefit, please refer to Fataawa 88409 and 83629.

Allaah Knows best.