For cycle

hi I’m having some trouble with this

for (i=11; i<=99; i++) {

    if (local.hitTest("p"+i)) {
        if (Key.isDown(49)) {
            "t"+i = 1;
        }
        if (Key.isDown(50)) {
            "t"+i= 2;
        }
        if (Key.isDown(51)) {
            "t"+i= 3;
        }
        if (Key.isDown(52)) {
            "t"+i= 4;
        }
        if (Key.isDown(53)) {
            "t"+i= 5;
        }
        if (Key.isDown(54)) {
            "t"+i= 6;
        }
        if (Key.isDown(55)) {
            "t"+i = 7;
        }
    }
        if (Key.isDown(56)) {
        "t"+i = 8;
    }
        if (Key.isDown(57)) {
        "t"+i = 9;
    }

}

it gives this error:

Left side of assignment operator must be variable or property.

in this source:
“t”+i

can someone help?