if-Abfrage mit radio-button "checked" defekt?

[glan]

Hallo,
ich kann in diesen Abfragen keine Fehler erkennen, trotzdem wird immer Sonntag selektiert.

$wtag=date("w");
...
if ($wtag = "7")
{
echo "                 <input type="radio" name="tg" value="Montag" checked> Montag\n";
} else {
echo "                 <input type="radio" name="tg" value="Montag"> Montag\n";
}
if ($wtag = "2")
{
echo "                 <input type="radio" name="tg" value="Dienstag" checked> Dienstag\n";
} else {
echo "                 <input type="radio" name="tg" value="Dienstag"> Dienstag\n";
}
if ($wtag = "3")
{
echo "                 <input type="radio" name="tg" value="Mittwoch" checked> Mittwoch\n";
} else {
echo "                 <input type="radio" name="tg" value="Mittwoch"> Mittwoch\n";
}
if ($wtag = "4")
{
echo "                 <input type="radio" name="tg" value="Donnerstag" checked> Donnerstag\n";
} else {
echo "                 <input type="radio" name="tg" value="Donnerstag"> Donnerstag\n";
}
if ($wtag = "5")
{
echo "                 <input type="radio" name="tg" value="Freitag" checked> Freitag\n";
} else {
echo "                 <input type="radio" name="tg" value="Freitag"> Freitag\n";
}
if ($wtag = "6")
{
echo "                 <input type="radio" name="tg" value="Samstag" checked> Samstag\n";
} else {
echo "                 <input type="radio" name="tg" value="Samstag"> Samstag\n";
}
if ($wtag = "1")
{
echo "                 <input type="radio" name="tg" value="Sonntag" checked> Sonntag\n";
} else {
echo "                 <input type="radio" name="tg" value="Sonntag"> Sonntag\n";
}

Danke im Voraus