Description of example
<script>
var inf, cmf;
//called on page load, we get and store the elements that hold the inches and cms
function init(){
inf = document.getElementById('in');
cmf = document.getElementById('cm');
}
//
function convert(){
var i = inf.value.replace(/ /,"");
if ( i ){
cmf.value = i * 2.54;
return;
}
//if there was nothing in the inches, check the cms
var c = cmf.value.replace(/ /,"");
if ( c ){
inf.value = c / 2.54;
}
}
//empties both fields
function reset(){
inf.value = "";
cmf.value = "";
}
</script>