foreign keys - username search in Django -

i want search username, way code set can search id in user model. how can search username? can't difficult, i'm failing see how done.

model

class incident(models.model):        incident_id = models.charfield(max_length=1000)        user_id = models.foreignkey(user) 

form

<form method='get' action='/search_incidents/'>         <div class="row">                <div class="form-group col-md-3">                 <label>incident id</label>                 <input type="text" name="incident_id" value="{{ incident_id_query }}" class="form-control"/>             </div>                       <div class="form-group col-md-3">                    <label>user id</label>                 <input type="text" name="user_id" value="{{ user_id_query }}" class="form-control"/>             </div>         </div> </form> 

view

@login_required def search_incidents(request):      if request.method == 'get':          incident_id_query = request.get.get('incident_id')         user_id_query = request.get.get('user_id')          try:             incident_id = str(incident_id_query)         except valueerror:             incident_id = none         try:             user_id = str(user_id_query)         except valueerror:             user_id = none          list = [incident_id,user_id]          if all(x none x in list): #check if `list` contains none             incident_list = none #this in case query comes empty         else: #perform query              incident_list = incident.objects.filter(incident_id=incident_id).filter(user_id=user_id)           return render(request, 'search_incidents.html', {              'incident_list' : incident_list         })