IPhone : On focus to next input field trigger keypad in Iphone

I am having issues with triggering keypad automatically in Iphone, when focus to next input field is done.

Can any one help with this please.

Following is jquery code I am using.

$('input[class*="form-control"]').keyup(function(event) {
    var $this = $(this);
    var currentLength = $this.val().length;
    var maximumLength = $this.attr('maxlength');
    // if we've filled up this input, go to the next if only numerics are entered.
    if ( (currentLength == maximumLength) && (!isNaN(this.value))) {
        //$('input').eq($(this).index('input') + 1).contentEditable = true;
        $('input').eq($(this).index('input') + 1).select();

    }
    //go to previous input if Backspace or Delete buton is pressed
    if((event.which == 8 || event.which == 46) && (maximumLength == 1)) {
        $(this).val('');
        $('input').eq($(this).index('input') - 1).val('').focus();
    }
});