Algo mejor
Código:
<script type="text/javascript">
var buffer="";
function ver(input){
if(buffer==""){
buffer=document.formulario[input].value;
document.formulario[input].value='';
}
else if(document.formulario[input].value==""){
document.formulario[input].value=buffer;
buffer="";
}else
{
buffer="";
}
}
</script>
Código HTML:
<form action="/" method="post" name="formulario">
<input type="text" name="in1" value="Escriba1" onFocus="ver(this.name)" onBlur="ver(this.name)" >
<input type="text" name="in2" value="Escriba2" onFocus="ver(this.name)" onBlur="ver(this.name)">
<input type="text" name="in3" value="Escriba3" onFocus="ver(this.name)" onBlur="ver(this.name)">
</form>