lib/Ext/form/Panel.js
function(cfg, target) {
        //<debug>
        Ext.Logger.warn('showMask is now deprecated. Please use Ext.form.Panel#setMasked instead');
        //</debug>

        cfg = Ext.isObject(cfg) ? cfg.message : cfg;

        if (cfg) {
            this.setMasked({
                xtype: 'loadmask',
                message: cfg
            });
        } else {
            this.setMasked(true);
        }

        return this;
    }
function(cfg, target) {
        //<debug>
        Ext.Logger.warn('showMask is now deprecated. Please use Ext.form.Panel#setMasked instead');
        //</debug>

        cfg = Ext.isObject(cfg) ? cfg.message : cfg;

        if (cfg) {
            this.setMasked({
                xtype: 'loadmask',
                message: cfg
            });
        } else {
            this.setMasked(true);
        }

        return this;
    }
Shows a generic/custom mask over a designated Element.
@param {String/Object} cfg Either a string message or a configuration object supporting
the following options:

{
message : 'Please Wait',
cls : 'form-mask'
}

@param {Object} target
@return {Ext.form.Panel} This form
@deprecated 2.0.0 Please use {@link #setMasked} instead.