<!DOCTYPE html>
<html>
<head>
<meta charset="utf-8">
<title>javascript - Obtener el valor de un input type=text de varias maneras</title>
<script>
function copiar() {
if( document.getElementById("text1").value == '261') {
document.getElementById("text2").value='mza';
}
else if( document.getElementById("text1").value == '11') {
document.getElementById("text2").value='bsas';
}
else if( document.getElementById("text1").value == '381') {
document.getElementById("text2").value='cba';
} else
document.getElementById("text2").value='';
;
}
function deshabilita()
{
if(document.getElementById('text2').value='')
{
document.getElementById('enviar').disabled=true;
}
else
{
document.getElementById('enviar').disabled=false;
}
}
</script>
<form>
<label></label>
<form name="form1" method="post" action="">
<label>
<input type="password" name="text1" id="text1" onBlur="copiar() deshabilita()">
<input type="text" name="text2" id="text2">
<input type="submit" name="Submit" value="Enviar">
<br>
</form>
</html>