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// if you are using onclick attribute you can write like this for example
<button type="button" onclick="myFunction('testParameter')"> Test Button</button>
<script>
function myFunction(myString){
console.log(myString)
}
</script>
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<input type="text" id="dt" value="" required oninvalid="setCustomValidity('Please enter e value to process!!')" oninput="setCustomValidity('')" >
<input type='button' value="Save" onclick="processRequest(document.getElementById('dt').value)">
<script>
window.onload=(()=>{document.querySelector("input[id='dt']").value=(new Date()).getFullYear();});
processRequest=((val)=>{
alert(val);
});
</script>