Connecting signals and slots help pls

[bod]

Hello,
I have a object on the left and a treewidget on the right.When I selected an item from the right, I want object to change its color.
Here is my code:

glWidget = new GLWidget;
tree = new QTreeWidget;
tree->setHeaderLabel("Items");
qtItem = new QTreeWidgetItem(tree);
qtItem->setText(0, tr("QtLogo"));
connect(qtItem , SIGNAL(isSelected()), glWidget, SLOT(setHighlighted()));

glWidget = new GLWidget;
tree = new QTreeWidget;
tree->setHeaderLabel("Items");
qtItem = new QTreeWidgetItem(tree);
qtItem->setText(0, tr("QtLogo"));
connect(qtItem , SIGNAL(isSelected()), glWidget, SLOT(setHighlighted()));

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However it gives me an error:

"\Window.cpp(50) : error C2664: 'bool QObject::connect(const QObject *,const char *,const QObject *,const char *,Qt::ConnectionType)' : cannot convert parameter 1 from 'QTreeWidgetItem' to 'const QObject *'
1> No user-defined-conversion operator available that can perform this conversion, or the operator cannot be called"

I did not understand the mistake, help me pls.