Hint Text not working

Hello, i need a little help text align with hint text not work together,why?

userLogin = Ti.UI.createTextField({
        color : '#817F81',
        hintText : 'Usuario',
        font : {
            fontSize : '18dp',
            fontFamily : 'HelvLight Regular'
        },
        height : '50dp',
        top : '48dp',
        left : '8dp',
        width : '95%',
        borderRadius : 3,
        backgroundColor : '#FFFFFF',
        borderColor : '#DAD6DA',
        borderWidth : '0.67dp',
        textAlign:'center',
        verticalAlign : Ti.UI.TEXT_VERTICAL_ALIGNMENT_CENTER,
        zIndex : 4,
    });