Java Script: Allow only Numeric Value, Decimal

function allowOnlyNumeric(e) {

var bName = navigator.appName; //alert(bName);

if(bName == "Microsoft Internet Explorer"){

var key_ie = window.event.keyCode;

//alert(key_ie);

if ( (key_ie > 47 && key_ie < 58) || key_ie == 46 || key_ie == 32 || key_ie == 45 )

return;

else

window.event.returnValue = null;

}else{

var key_mozila = e.which;

//alert(key_mozila);

if ( (key_mozila > 47 && key_mozila < 58) || key_mozila == 46 || key_mozila == 32 || key_mozila == 45 )

return;

else

return false;

}

}

onkeypress="javascript:return allowOnlyNumeric(event);"