I need reload a JSF component when press a key, i have the following code

```
<script>
    document.onkeypress=teclaPulsada
    function teclaPulsada()
    {
    var teclaASCII=event.keyCode
    var teclaCHAR=String.fromCharCode(teclaASCII)
    if (teclaASCII==49 )
    {   
    document.getElementById("formularioImagen").setAttribute("value", "TiffBean.getImagen()")
    }
    else if ( teclaASCII==50)
    {
    alert("disminuir")
    }
    }
</script>
<h:form id="formularioImagen">
        <p:graphicImage  id="imagen" value="#{TiffBean.getImagen()}" width="1000" height="1500" border="5" cache="FALSE" >
        </p:graphicImage>
</h:form>

```

when I run the image no reload