This my code

```
encrypt(plaintxt){
    const secretKey = '12456780123456';
    const iv = "124567890123456";

    let a = "awal";
    AesCrypto.encrypt(plaintxt,secretKey,iv).then(cipher=>{
        a = cipher;
    }).catch(err=>{
        a = err;
    });
    return a;
}

```

How i can set value for variable a in the AesCrypto.encrypt function? Thanks.