IFrame maps problem

So I have inserted an IFrame into our contacts form that contains bing maps. I have also created an event to run the following jscript so that when the contact form loads it will automatically search the address. My Problem is that when u load a contact now it will let you use it for about 5 seconds and then automatically skip down to the IFrame as it has found the search address. Is there anyway to stop this? 

function MapURL() 

{ 

var ContactStreet = crmForm.all.address1_line1.DataValue; 

var ContactCity = crmForm.all.address1_city.DataValue; 

var ContactState = crmForm.all.address1_stateorprovince.DataValue; 

var ContactZip = crmForm.all.address1_postalcode.DataValue;

var MapURL = "http://www.bing.com/maps/default.aspx?v=2&where1=" + ContactStreet + " " + ContactCity + " " + ContactState + " " + ContactZip;

if (MapURL != null) 

   { 

      crmForm.all.IFRAME_Maps.src = MapURL; 

   } 

}