function on_load(proc) {
  var form;       // Primer formulario del documento.
  var n;          // Cantidad de elementos del formulario.
  var i;          // Índice del elemento en curso.
  var element;    // Elemento del formulario.

  if (document.forms.length > 0) {
    form = document.forms[0];
    n = form.elements.length;
    for (i = 0; i < n; ++i) {
      element = form.elements[i];
      if (element.type == "text" && !element.disabled && !element.readOnly) {
        element.focus();
        break;
      } else if (element.type == "textarea" && !element.disabled && !element.readOnly) {
        element.focus();
        break;
      } else if (element.type == "password" && !element.disabled && !element.readOnly) {
        element.focus();
        break;
      } else if (element.type == "file" && !element.disabled && !element.readOnly) {
        element.focus();
        break;
      } else if (element.type == "submit" && !element.disabled && element.value != "Eliminar") {
        element.focus();
        break;
      } else if (element.type == "reset" && !element.disabled) {
        element.focus();
        break;
      } else if (element.type == "button" && !element.disabled) {
        element.focus();
        break;
      /***
      ***/
      } else if (element.type == "select-one" && !element.disabled) {
        element.focus();
        break;
      } else if (element.type == "select-multiple" && !element.disabled) {
        element.focus();
        break;
      /***
      ***/
      }
    }
  }
}

function showImage(url, width, height, target, title) {
    window.open("includes/show_image.php?url="+url+"&width="+width+"&height="+height+"&title="+title, target, "fullscreen=no, channelmode=no, toolbar=no, location=no, directories=no, status=no, menubar=no, scrollbars=no, resizable=no, width="+width+", height="+height+", top=100, left=100", false);
}

/***
Syntax
window = object.open([URL [, name [, features [, replace]]]])

Parameter Description
URL  String specifying the URL of the document to display. If no URL is specified, a new window with about:blank will be displayed.
name  Optional. String specifying the name of the window. This name is used for TARGET on a FORM or an A.
features  Optional. String specifying the window ornaments to display. The following table lists the supported features. Syntax  Description
fullscreen={ yes | no | 1 | 0 }  Specifies whether to display the browser in a full-screen or normal window. Default is no.
Use full-screen mode carefully. Because this mode hides the browser's title bar and menus, you should always provide a button or other visual clue to help the user close the window. ALT+F4 will also close the new window.

channelmode={ yes | no | 1 | 0 }  Specifies whether to display the window in theater mode and show the channel band.
toolbar={ yes | no | 1 | 0 }  Specifies whether to display the browser toolbar, making buttons such as Back, Forward, and Stop available.
location= { yes | no | 1 | 0 }  Specifies whether to display the input field for entering URLs directly into the browser.
directories = { yes | no | 1 | 0 }  Specifies whether to add directory buttons. Default is no.
status={ yes | no | 1 | 0 }  Specifies whether to add a status bar at the bottom of the window. Default is yes.
menubar={ yes | no | 1 | 0}  Specifies whether to display the menu bar. Default is yes.
scrollbars={ yes | no | 1 | 0}  Specifies whether to display horizontal and vertical scroll bars. Default is yes.
resizable={ yes | no | 1 | 0}  Specifies whether to display resize handles at the corners of the window.
width=number  Sets the width of the window, in pixels. Minimum value should be 100.
height=number  Specifies the height of the window, in pixels. Minimum value should be 100.
top=number  Specifies the top position, in pixels. This value is relative to the upper-left corner of the screen.
left=number  Specifies the left position, in pixels. This value is relative to the upper-left corner of the screen.

replace  Optional. A boolean value specifying whether the URL that is loaded into the new page should create a new entry in the window's browsing history or replace the current entry in the browsing history. If true, no new history entry is created.
***/