//Adds value and its name to querystring
function AddToQuery(q, valname, val){
 if (q.indexOf('?')<0) {
   q += '?'
 } else {
 var pv = q.indexOf(valname+'=');
 if (pv >= 0){
  var amp = q.indexOf('&', pv);
  if (amp<0) {
   q = q.substr(0, pv) 
  } else {
   q = q.substr(0, pv) + q.substr(amp+1) + '&'
  }
 } else {
  if (q.substr(q.length-1)!='?') q += '&'
 };
 };
 q += valname + '=' + val
 return q
};

//Huge-asp upload preview sample
//http://www.pstruh.cz

function isImage(file){
  //Get a file extension
  var ext = file.substr(file.lastIndexOf('.')).toLowerCase()

  //Check extension to image types.
  
  return '.jpg,.gif'.indexOf(ext+',') >= 0
};

var lastfieldname = ''
var filenamechecked = ''
function preview(i) {
  //get current input preview
  var file = i.value

  if (file.length<=0) return;

  //or get get preview for one of form field
  //var file = file_upload.SourceFile1.value
  var ipreview = document.all('ipreview')
  if (isImage(file)) {
    //Show preview for the image.
    ipreview.src = 'file://' + file

    ImageName.innerHTML = 'Image preview'
  } else {
    //some default image for preview
    ipreview.src = 'res://shdoclc.dll/warning.gif'
    
    if (filenamechecked != i.value) {
      filenamechecked = i.value
      alert('Please choose an image file (<%=imageExts%>)');
    };
  };
  lastfieldname = i.name
}

//window.onerror = donotmsgboxes;
function donotmsgboxes(msg,url,line)
{  // we do not need error messages
  return true
}