Lets assume that this is a sample page of yours which has the select option with the id "dropdown"
HTML
<html>
<body>
<p>What you are looking for? Iam looking for
<select id = "dropdown" >
<option value="zero" selected>Select Option</option>
<option value = "one">Duckduckgo</option>
<option value = "two">Qwant</option>
<option value = "three">Jamun Search</option>
</select>
</p>
</body>
//Javascript
function showDrop(){
var paragraphTag = document.getElementById('list');
paragraphTag.style.display = "none";
var selected = document.getElementById('dropdown');
selected.style.display = "block";
}
function redirectFunction(){
var selected = document.getElementById('dropdown');
var selectValue = selected.options[selected.selectedIndex].value;
if(selectValue == "one"){
window.location.href = "http://www.duckduckgo.com";
}
else if(selectValue == "two"){
window.location.href = "http://www.qwant.com";
}
else if(selectValue == "three"){
window.location.href = "http://www.jamunsearch.rf.gd";
}
else {
alert("Please Select An Option To Proceed!")
}
}
/* CSS */
.dropdown {
display: none;
}
<!--HTML-->
<html>
<body>
<p>What you are looking for? Iam looking for</p> <p id="list" onclick="showDrop()">__________</p>
<select id = "dropdown" class="dropdown" onchange="redirectFunction()">
<option value = "zero" selected>Select Option</option>
<option value = "one">Duckduckgo</option>
<option value = "two">Qwant</option>
<option value = "three">Jamun Search</option>
</select>
</p>
</body>
</html>
When the user clicks the '_____' it will be hidden and the select drop box will be visible to be selected.
The redirectFunction() will be executed when the user selects one of the options and the drop down button will be deleted(display:hidden). The script takes the value of the selected option i.e., zero,one,two or three. And then it checks with the values in the code. window.location.href("http://www.example.com")
will redicted the user to Example.com
You can change that url to your wordpress urls.
If the user doesn't select and clicks the button, the page will alert the user to select one option.
If you wanted to check the condition with the select name refer this post Get the Select Option Value