<input autocomplete="off" class="form-control amount input-lg" id="inputAmountCrypto" onchange="updateCurrencyLTC(value)" name="crypt_amount" placeholder="0.00144467" type="text" value="">
<?php echo "<script>"; echo "function updateCurrencyLTC(value) {"; echo "document.getElementById(\"inputAmountUsd\").innerHTML = value * $ltc;"; echo "}"; echo "</script>" ?>
<input autocomplete="off" class="form-control amount input-lg" id="inputAmountCrypto" onchange="updateCurrencyLTC(value)" name="crypt_amount" placeholder="0.00144467" type="text" value=""> <div id='inputAmountUsd'></div> <script type='text/javascript'> function updateCurrencyLTC(value) { document.getElementById("inputAmountUsd").innerHTML = value; }; </script>
<input class="form-control amount input-lg" id="inputAmountUsd" value="" name="usd_amount" placeholder="" type="text" autocomplete="off">
function updateCurrencyLTC(value) { document.getElementById("inputAmountUsd").value = value; };
<?php echo "<script> function updateCurrencyLTC(value) { var c = $ltc; document.getElementById(\"inputAmountUsd\").value = value * c; } </script>" ?>