/*****************************************/
function trim(value){
  var len = value.length;
  var i, j, retVar;
  for(i=0; i<len; i++){
    if (value.charAt(i) != " ") break;
  }
  for(j=len-1; j>=0; j--){
    if (value.charAt(j) != " ") break;
  }
  if (j < i) retVar = "";
  else retVar = value.substring(i,j+1);
  return retVar;
}
/*****************************************/
function check_eml(field) {
	if (field.value == null) return false;
   var i = field.value.lastIndexOf('@');
   var j = field.value.lastIndexOf('.');
   return (i != -1 && j != -1 && i <= j);
}
/*****************************************/
function check_fle(field, kind, filetype){
  var tmp = trim (field.value);
  var indexOfDot = tmp.lastIndexOf(".");
  var extension = tmp.substring(indexOfDot+1,tmp.length);
  if (extension.toLowerCase() != filetype.toLowerCase() ) {
//    alert("Error: " + field.value + "\nFile Type must be : '." + filetype +"'");
    alert(" اشتباه" + "\n" +  field.value + "\n فايل بايد از اين نوع باشد: \n  " + filetype );
    return false;
  }
  return true;
}
/*****************************************/
function checkFileInput(form, kind, extension)
{
    var someField = false;
    var ret = true;
    for(var fieldNum=0; fieldNum < fields.length; fieldNum++) {
        var field = form.elements[fields[fieldNum]];
		if (field.name == "email") {
			ret =check_eml(field);
			if (ret == false) {
				alert("Please enter your correct email!  \n لطفا آدرس الکترونیکی خود را تصحیح کنید"); 
				return false;
			}
		}
        else if (field.value != null && field.value != ""){
        	someField = true;
        	ret = check_fle(field, kind, extension);
        	if (ret == false)return false;
        };
    }
    if (someField == false){
    	alert("Please enter some file! \n لطفا يک فايل انتخاب کنيد");
    	return false;
    }
    return ret;
}