Untitled

<html lang="pt-br">
	<head>
		<meta charset="utf-8"></meta>
	<script>
	for (j=1; j<=5; j++){
			for (x=1; x<=5; x++){
				document.write("<input type='text' size=1  id='"+j+x+"'></input>");
				}
				document.write("<br>");
		}
				document.write("Acabou");

				function mostrar(){
					var linha=document.getElementById("c1").value;
					var coluna=document.getElementById("c2").value;
					var conteudo=document.getElementById(linha+coluna).value;
					alert(conteudo);
					}
	</script>
	</head>
	<body>
		<input type="text" id="c1" size=1></input>
		<input type="text" id="c2" size=1></input>
		<input type="button" id="c2" value="mostrar" onclick="mostrar()" size=2></input>
	</body>
</html>