how can i write a letter to director asking for visa approval for my daughter because my husband lost his job
Please see my corrections above. I think I have understood what you want. A director (someone in charge of a company) can't approve a visa application. Visa applications are considered by staff at a national embassy or consulate. I don't know what relevance you think your husband's employment status has.
In any case, we don't write letters for people. You need to try to write the letter yourself, post it in this section of the forum and then someone will look at it.
Remember - if you don't use correct capitalisation, punctuation and spacing, anything you write will be incorrect.