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Answer» To do something interesting with HTML elements, we must first be able to UNIQUELY identify which element we want. In the example
<BODY>
<form action="">
<input type="button" id="USELESS" name="mybutton" value="doNothing" />
</form>
</body>
We can use the "getElementById" method (which is GENERALLY preferred)
document.getElementById("useless").style.color = "red";
or we can use the older hierarchical navigation method,
document.forms[0].mybutton.style.color = "blue";
Notice that this uses the "name" attribute of the element to locate it.
# Example of Accessing Elements in a DOM.
<script type="text/javascript" >
function showStatus() {
var selectWidget = document.forms.beerForm.elements["beer"];
var myValue = selectWidget.options[selectWidget.selectedIndex].value;
alert('You DRANK a \"'+ myValue +"\"");
return true;
}
</script>
<form name="beerForm" action="">
<select name="beer">
<option selected="selected">Select Beer</option>
<option>Heineken</option>
<option>Amstel Light</option>
<option>Corona</option>
<option>Corona Light</option>
<option>Tecate</option>
</select>
<input type="button" name="submitbutton" value="Drink"
onclick="showStatus()" />
</form> To do something interesting with HTML elements, we must first be able to uniquely identify which element we want. In the example
<body>
<form action="">
<input type="button" id="useless" name="mybutton" value="doNothing" />
</form>
</body>
We can use the "getElementById" method (which is generally preferred)
document.getElementById("useless").style.color = "red";
or we can use the older hierarchical navigation method,
document.forms[0].mybutton.style.color = "blue";
Notice that this uses the "name" attribute of the element to locate it.
# Example of Accessing Elements in a DOM.
<script type="text/javascript" >
function showStatus() {
var selectWidget = document.forms.beerForm.elements["beer"];
var myValue = selectWidget.options[selectWidget.selectedIndex].value;
alert('You drank a \"'+ myValue +"\"");
return true;
}
</script>
<form name="beerForm" action="">
<select name="beer">
<option selected="selected">Select Beer</option>
<option>Heineken</option>
<option>Amstel Light</option>
<option>Corona</option>
<option>Corona Light</option>
<option>Tecate</option>
</select>
<input type="button" name="submitbutton" value="Drink"
onclick="showStatus()" />
</form>
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