Entweder:
echo "
<div style="text-align:center;">
<a onMouseOver="y=6">Hallo<a></div>";
(" escaped) oder
echo '
<div style="text-align:center;">
<a onMouseOver="y=6">Hallo<a></div>';
Entweder:
echo "
<div style="text-align:center;">
<a onMouseOver="y=6">Hallo<a></div>";
(" escaped) oder
echo '
<div style="text-align:center;">
<a onMouseOver="y=6">Hallo<a></div>';