Set Minimum Map scale

[EssamYoussif]

How can i Set minimum map scale whatever zoom out done?

[TristanForward2]

You can try something like this

featureLayer.minScale = 100000; <!--Min scale at which appears-->
featureLayer.maxScale = 0;

or

Within the declarations tags
<esri:GraphicsLayer id="myGraphicsLayer" minScale="1500000"/>

Go here for overall understanding
http://resources.esri.com/help/9.3/arcgisserver/apis/flex/apiref/com/esri/ags/layers/Layer.html#isIn...