facil... mira:
Código HTML:
<script language="javascript">
function pasarvariables() {
var f = document.form1;
document.location.href = "otrapagina.asp?nom=" + f.texto.value;
}
</script>
<form name="form1" method="post" action="">
<input type="text" name="texto" value="hola">
</form>