I should be able to save the username without changing the password.and validate #frmMyprofile only if current password is not blank.How to do that?

Javascript Validation code:

$('#frmMyProfile').validate({

        rules: {

            user[current_password]: required,

            user[password]: {

                required: true,

                minlength: 6

            },

            user[password_confirmation]: {

                required: true,

                minlength: 6,

                equalTo: #user_password

            }

        },

        messages: {

            user[current_password]: Please enter your current password,

            user[password]: {

                required: Please enter new password,

                minlength: Please enter at least 6 characters

            },

            user[password_confirmation]: {

                required: Please enter confirm password,

                equalTo: Please enter the same value as the new password.

            }

        }

});

HTML:
I should be able to save only user name or only password or both.It should only validate if current password is not blank.

<form accept-charset=UTF-8 action=/users class=form-stacked id=frmMyProfile method=post novalidate=novalidate><div style=margin:0;padding:0;display:inline><input name=utf8 type=hidden value=✓><input name=_method type=hidden value=put><input name=authenticity_token type=hidden></div>          <div class=form-horizontal>

                  <div class=form-row control-group>

                    <div class=input>

                      <label class=control-label for=user_id>Email ID</label>

                      <div class=controls>

                        <input disabled=disabled type=email [email protected]>

                      </div>

                    </div>

                  </div>

                </div>

                <div class=form-horizontal>

                  <div class=form-row control-group>

                    <div class=input>

                      <label class=control-label for=user_name>User Name</label>

                      <div class=controls>

                        <input name=user[name] type=text value=test class=valid>

                      </div>

                    </div>

                  </div>

                </div>

                <div class=form-horizontal>

                  <div class=form-row control-group>

                    <div class=input>

                      <label class=control-label for=user_current_password>Current Password</label>

                      <div class=controls>

                        <input id=user_current_password name=user[current_password] size=30 type=password>

                      </div>

                    </div>

                  </div>

                  <div class=form-row control-group>

                    <div class=input>

                      <label class=control-label for=user_password>New Password</label>

                      <div class=controls>

                        <input id=user_password name=user[password] size=30 type=password>

                      </div>

                    </div>

                  </div>

                  <div class=form-row control-group>

                    <div class=input>

                      <label class=control-label for=user_password_confirmation>Confirm Password</label>

                      <div class=controls>

                        <input id=user_password_confirmation name=user[password_confirmation] size=30 type=password>

                      </div>

                    </div>

                  </div>

                  <div class=form-row control-group>

                    <div class=input>

                      <label></label>

                    </div>

                    <div class=controls>

                      <input name=version type=hidden value=v2>

                      <button class=btn btn-primary qbol-button-save type=submit>Save</button>

                      <button class=btn qbol-button-clear type=reset>Clear</button>

                    </div>

                  </div>

                </div>

      </form>