enabling a checkbox when another checkbox is checked using javascript

Ask Time：2014-01-16T10:59:52 Author：user2108839

I am trying to enable a disabled checkbox when another checkbox is checked by using javascript. I believe my problem is when I am trying to pass the form information into the javascript.

Here is my HTML:

 <form id="checkboxes">
            <input type="checkbox" name="checkboxa" onclick="javascript:ToggleSwitch(form)" />1
            <input type="checkbox" name="checkboxb" disabled="true" />2
        </form>

Here is my Javascript:

  <script type="text/javascript">
var form= document.getElementById("checkboxes")
function ToggleSwitch(form) {
    if (form.elements["checkboxa"].checked) 
   form.elements["checkboxb"].disabled = false
} else {
   form.elements["checkboxb"].disabled = true
}
</script>

Author:user2108839，eproduced under the CC 4.0 BY-SA copyright license with a link to the original source and this disclaimer.
Link to original article：https://stackoverflow.com/questions/21152581/enabling-a-checkbox-when-another-checkbox-is-checked-using-javascript

Leo Zhao :

You missed { and } in your javascript. Try this:\n\nvar form= document.getElementById(\"checkboxes\")\nfunction ToggleSwitch(form) {\n if (form.elements[\"checkboxa\"].checked) { // here\n form.elements[\"checkboxb\"].disabled = false\n } else {\n form.elements[\"checkboxb\"].disabled = true\n }\n} // and here\n",

2014-01-16T03:03:12

iJade :

Change you onclick event like this\n\nonclick=\"javascript:ToggleSwitch(this.form)\"\n\n\nand also you don't need to var form= document.getElementById(\"checkboxes\") since you are already passing it as a parameter from onclick event.\n\nAnd you are also missing a parenthesis\n\nHere is the js\n\n <script>\n function ToggleSwitch(form) {\n if (form.elements[\"checkboxa\"].checked) {\n form.elements[\"checkboxb\"].disabled = false\n } else {\n form.elements[\"checkboxb\"].disabled = true\n }\n }\n\n</script>\n\n\nAnd here is the html\n\n <form id=\"checkboxes\">\n<input type=\"checkbox\" name=\"checkboxa\" onclick=\"javascript:ToggleSwitch(this.form)\" />1\n<input type=\"checkbox\" name=\"checkboxb\" disabled=\"disabled\" />2\n</form>\n\n\nAnd here is a demo",

2014-01-16T03:22:59

enabling a checkbox when another checkbox is checked using javascript