To have a child
First Mantra: Devaki Sut Govind Vasudeva Jagatpate, Dehime Tanayam Krishna Tvamaham Sharanam Gatha
Some unknown amazing facts which were unheard about Lord Krishna
Second Mantra: Clean Glau Clean Shyamlangay Namah
Those who wish to have children, husband and wife together should chant both these mantras on the day of Janmashtami and pray to the Lord for fulfillment of their wishes.