F5 key board key disable code using javascript

// F5 key board key disable code using javascript
// refresh button in browser also disabling using this following javascript code
//-------------------------------------------------------------------------------------------------
function disablekeyboardnavigation(e)
{
var input_key = "";


if(window.event) {
input_key = event.keyCode; //IE
} else {
input_key = e.which; //firefox
}
if (input_key == 0 ) //F5
{
alert('This operation is not allowed');
return false;
}


return true;
}
// in html body tag place the following code
// body onLoad="disablekeyboardnavigation(this);"
//-------------------------------------------------------------------------------------------------