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POUncaught TypeError: Cannot call method 'toString' of null
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  1. POUncaught TypeError: Cannot call method 'toString' of null
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    copied!<p>I'm trying to create a class in JavaScript to validate a form. That'll check the form elements and validate a field if it has a specific attribute.</p> <p>However, the call to <code>getAttribute</code> isn't returning a value. It doesn't get the value inside another variable, but, if I print, it works well.</p> <p>Here's the code for my class:</p> <pre><code>function valida() { document.getElementById("msgDiv").innerHTML=""; var totalErros=0; var x=document.getElementById("frm1"); for (var i=0;i&lt;x.length;i++){ var input=document.getElementsByTagName("input")[i]; var campo=input.getAttribute("id"); var tipo=input.getAttribute("tipo"); var nome=input.getAttribute("nome"); var id=campo.toString(); //the error goes here //var valor=_$(id).value; alert(campo); switch (tipo) { case "obrigatorio": if(document.getElementById(id).value==""){ document.getElementById("msgDiv").innerHTML+="Deu erro no campo "+nome+"&lt;br /&gt;"; totalErros++;} break case "oemail": if(document.getElementById(id).value==""){ document.getElementById("msgDiv").innerHTML+="Deu erro no campo "+nome+"&lt;br /&gt;"; totalErros++;} break case "email": if(!ValidaEmail(document.getElementById(id).value)){ document.getElementById("msgDiv").innerHTML+="O "+nome+" que você informou é inválido "+document.getElementById(id).value+" &lt;br /&gt;"; totalErros++;} break default: document.getElementById("msgDiv").innerHTML+="&lt;br /&gt;"; } } if(totalErros==0) { document.getElementById("msgDiv").innerHTML="Agora foi "+ totalErros; return true; } } </code></pre>
 

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