Something

function openImageSelector(imagename, formname) {
    childWindow = open('test2.php', "photoselect_"+imagename+formname, 'resizable=no, width=200, height=400');
    if(childWindow.opener == null) {
        childWindow.opener = self;
    }
    
    childWindow.imagename = imagename;
    childWindow.formname = formname;
    
}

function setSelectedImage(photoid) {
    var imageidfield = self.imagename + "_id";
    opener.document.getElementById(imagename).src="/photoAdmin/getImage/iid/" + photoid;
    opener.document.forms[formname].elements[imageidfield].value = photoid;
    alert(opener.document.getElementById(imagename).src);
    self.close();
    
}