如何根据表单的每个不同实例在变量中使用不同的值？

var formInstance1 = document.getElementById("form1").value;
var formInstance2 = document.getElementById("form2").value;
var formInstance3 = document.getElementById("form3").value;

if (formInstance1 == "exampleValue1") {
    var variable1 = formInstance1;
} else if (formInstance2 == "exampleValue2") {
    var variable1 = formInstance2;
} else if (formInstance3 == "exampleValue3") {
    var variable1 = formInstance3;
}