How to NOT show glyphicon-ok if field is left empty?

Question

I have a "txtPhone" input filter that is NOT mandatory, but can accept only Phone Numbers, so:

 <label class="control-label">Phone</label>
<input type="text" id="txtPhone" class="form-control intonly" maxlength="12" placeholder="Phone" name="Phone">

Bootstrap Validation

Phone: {
                        validators: {
                            regexp: {
                                regexp: /^((091|\+91)?|\((091|\+91)?\)|(91)?|\(91\)|0)? ?[7-9][0-9]{9}$/,
                                message: 'The Indian Phone No must contain 10 digits'
                            },

                        }
                    },

But when i clicking submit button tick shown in textbox.

Answer 1

After Long struggling JesusGrace i find the answer

  Bootstrap Validation

     Phone: {
                     enabled: false,
                    validators: {
                        regexp: {
                            regexp: /^((091|\+91)?|\((091|\+91)?\)|(91)?|\(91\)|0)? ?[7-9][0-9]{9}$/,
                            message: 'The Indian Phone No must contain 10 digits'
                        },

                    }
                },


        .on('keyup', '[name="Phone"]', function () {
                var isEmpty = $(this).val() == '';
                $('#form1')
                       .formValidation('enableFieldValidators', 'Phone', !isEmpty);
                // Revalidate the field when user start typing in the Phone field
                if ($(this).val().length == 1) {
                    $('#form1').formValidation('validateField', 'Phone')
                }
            })