Get/Set field selections

Field_Selections.js

    /**
    *   Gets the current cursor position in a textfield
    *   to determine where to delete/update a character.
    *   @param {Element} field The raw field to get the cursor pos from.
    *   @return {Number} The index for the position of the cursor. 
    */
    function getCursorPosition( field ) {
        if ( field != null ) {
            // IE
            if ( document.selection ) {
                field.focus();
                var sel = document.selection.createRange();
                sel.moveStart( 'character', -field.value.length );
                return sel.text.length;
            }
            // Others
            else if ( field.selectionStart || field.selectionStart == '0' ) {
                return field.selectionStart;
            }
        }
        // Something went wrong.
        return -1;
    }
    
    /**
    *   Sets the cursor position to a previous state
    *   if the field was updated somewhere in the middle.
    *   @param {Element} field The raw field.
    *   @param {Number} pos The position to set to.
    */
    function setCursorPosition( field, pos ) {
        if ( field != null ) {
            // IE
            if ( field.createTextRange ) {
                var range = field.createTextRange();
                range.move('character', pos);
                range.select();
            }
            // Others
            else if ( field.selectionStart ) {
                field.focus();
                field.setSelectionRange( pos, pos );
            }
            // Something's wrong. Just focus on it.
            else
                field.focus();
        }
    }