How to set a lookup Value using javascript

Question

Hi 

  I have a  "country"  look up field in Contact entity.When i select an account in contact i want to auto populate the Country field.

 I have the following code

  

  var lookupData = new Array();      
  var lookupItem= new Object();   
//Set the id, typename, and name properties to the object.   
lookupItem.id = countryId;   //GUID
lookupItem.typename = 'country'; 
lookupItem.name = countryname;

// Add the object to the array.    
lookupData[0] = lookupItem; 
Xrm.Page.getAttribute("new_country").setValue(lookupData);
This code is displaying the country value in Look Up field but the image is not displaying and  when clicking on the country 
its not opening.
Can anybody help me 
Thanks

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Thanks