marking a radio input as slected when page is loaded

I have two radio buttons. I want one of them to be shown as selected when the page loads. Which property I should use, and how?

Example:

<input type="radio" name="musictype2" value="rock" de开发者_开发知识库fault> Rock<br>
<input type="radio" name="musictype2" value="alternative"> Alternative<br>

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<input type="radio" name="test" value="2" checked="checked" />test

like this?

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<input type="radio" name="genreselect" value="rock" checked="checked" />
<input type="radio" name="genreselect" value="alternative" />

In this case "rock" is preselected.

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<form>
    <input type="radio" name="genre" value="rock" checked /> Rock<br />
    <input type="radio" name="genre" value="alternative" /> Alternative
</form>

This is the correct way. The name attribute needs to be the same in order for them to switch between.

Check it here.

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This is how you use the checked attribute:

<input type=radio name="my_name" VALUE="my_value" checked />